Same, but for me L4D2 uses all available memory (2G) instantly (during gameplay). It causes troubles like low performance, crashing chrome tabs and plugins. That's true for HL2DM, GM and possibly any source game.
In GM I can't play on heavily modded servers. It looks like memory leak, when I wait minute for bash promt (to kill process).

Same, but with 4GB RAM.
The problem occured only recently with my switch to Arch.
On Chakra (xorg-server 1.13 & Catalyst 13.4), L4D2 ran just fine.

Specs:

Linux localhost 3.10.3-1-ARCH #1 SMP PREEMPT Fri Jul 26 11:26:59 CEST 2013 x86_64 GNU/Linux
Xorg-server 1.14.2
Radeon HD 6670 with Catalyst 13.7 beta

Description:

Sometimes it occurs on entering a game, sometimes steam just crashes on entering a l4d2 game but most of the time it happens on shutting down left4dead2.

Then the process
~/.local /share/Steam/ubuntu2_32/steam steam://rungameid/550
will occupy 100% CPU and RAM, including heavy swapping.

After a while it goes down to some 3% cpu usage but still, the process isn't closed.
Killing it with SIGTERM works but only a tiny portion of RAM is really released then, the system still swapping.
With the process killed, these approx. 2GB of unusual ram usage aren't listed in the process table but are still occupied in buffers/cache, seemingly unassigned to any process.

free -m
             total       used       free     shared    buffers     cached
Mem:          3955       3711        244          0         11        208
-/+ buffers/cache:       3491        464
Swap:         2047        456       1591

Log:

$ steam steam://rungameid/550
Running Steam on arch  64-bit
STEAM_RUNTIME is enabled automatically
Installing breakpad exception handler for appid(steam)/version(1374875626_client)
Installing breakpad exception handler for appid(steam)/version(1374875626_client)
unlinked 0 orphaned pipes
Installing breakpad exception handler for appid(steam)/version(1374875626_client)
Fontconfig error: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 70: non-double matrix element
Fontconfig error: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 70: non-double matrix element
Fontconfig warning: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 78: saw unknown, expected number
[0730/182229:WARNING:proxy_service.cc(958)] PAC support disabled because there is no system implementation
Installing breakpad exception handler for appid(steam)/version(1374875626_client)
Installing breakpad exception handler for appid(steam)/version(1374875626_client)
Installing breakpad exception handler for appid(steam)/version(1374875626_client)
PulseAudio connect failed (used only for Mic Volume Control) with error: Access denied
Installing breakpad exception handler for appid(steam)/version(1374875626_client)
Installing breakpad exception handler for appid(steam)/version(1374875626_client)
Installing breakpad exception handler for appid(steam)/version(1374875626_client)
Installing breakpad exception handler for appid(steam)/version(1374875626_client)
Generating new string page texture 2: 48x256, total string texture memory is 49,15 KB
Generating new string page texture 3: 384x256, total string texture memory is 442,37 KB
Installing breakpad exception handler for appid(steam)/version(1374875626_client)
/home/buildbot/buildslave_steam/steam_rel_client_ubuntu12_linux/build/src/common/crypto.cpp (1633) : Assertion Failed: cubInput > 0
Assert( Assertion Failed: cubInput > 0 ):/home/buildbot/buildslave_steam/steam_rel_client_ubuntu12_linux/build/src/common/crypto.cpp:1633

Installing breakpad exception handler for appid(steam)/version(1374875626_client)
Uploading dump (out-of-process) [proxy '']
/tmp/dumps/crash_20130730182231_13.dmp

** (steam:26968): WARNING **: replace_settings: error updating connection /org/freedesktop/NetworkManager/Settings/0 settings: (1) type
roaming config store loaded successfully - 824 bytes.
migrating temporary roaming config store
Adding license for package 0
Adding license for package 36
Adding license for package 2482
Adding license for package 4357
Adding license for package 8535
Adding license for package 11080
Adding license for package 12573
Adding license for package 13408
Adding license for package 14695
Adding license for package 16134
Adding license for package 19098
Adding license for package 26482
Adding license for package 27214
ExecCommandLine: "/home/michael/.local/share/Steam/ubuntu12_32/steam steam://rungameid/550"
ExecSteamURL: "steam://rungameid/550"
System startup time: 8,88 seconds
/usr/bin/env: python: Datei oder Verzeichnis nicht gefunden
Generating new string page texture 70: 256x256, total string texture memory is 704,51 KB
Game update: AppID 550 "Left 4 Dead 2 (Beta)", ProcID 27057, IP 0.0.0.0:0

(steam:26968): LIBDBUSMENU-GLIB-WARNING **: Trying to remove a child that doesn't believe we're it's parent.

(steam:26968): LIBDBUSMENU-GLIB-WARNING **: Trying to remove a child that doesn't believe we're it's parent.

(steam:26968): LIBDBUSMENU-GLIB-WARNING **: Trying to remove a child that doesn't believe we're it's parent.

(steam:26968): LIBDBUSMENU-GLIB-WARNING **: Trying to remove a child that doesn't believe we're it's parent.

(steam:26968): LIBDBUSMENU-GLIB-WARNING **: Trying to remove a child that doesn't believe we're it's parent.

(steam:26968): LIBDBUSMENU-GLIB-WARNING **: Trying to remove a child that doesn't believe we're it's parent.

(steam:26968): LIBDBUSMENU-GLIB-WARNING **: Trying to remove a child that doesn't believe we're it's parent.

(steam:26968): LIBDBUSMENU-GLIB-WARNING **: Trying to remove a child that doesn't believe we're it's parent.

(steam:26968): LIBDBUSMENU-GLIB-WARNING **: Trying to remove a child that doesn't believe we're it's parent.

(steam:26968): LIBDBUSMENU-GLIB-WARNING **: Trying to remove a child that doesn't believe we're it's parent.

(steam:26968): LIBDBUSMENU-GLIB-WARNING **: Trying to remove a child that doesn't believe we're it's parent.

(steam:26968): LIBDBUSMENU-GLIB-WARNING **: Trying to remove a child that doesn't believe we're it's parent.

(steam:26968): LIBDBUSMENU-GLIB-WARNING **: Trying to remove a child that doesn't believe we're it's parent.
SDL video target is 'x11'
Installing breakpad exception handler for appid(gameoverlayui)/version(20130726142109_client)
Installing breakpad exception handler for appid(gameoverlayui)/version(1.0_client)
Installing breakpad exception handler for appid(gameoverlayui)/version(1.0_client)
Installing breakpad exception handler for appid(gameoverlayui)/version(1.0_client)
Fontconfig error: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 70: non-double matrix element
Fontconfig error: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 70: non-double matrix element
Fontconfig warning: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 78: saw unknown, expected number
[0730/182239:WARNING:proxy_service.cc(958)] PAC support disabled because there is no system implementation
Using breakpad crash handler
Setting breakpad minidump AppID = 550
Forcing breakpad minidump interfaces to load
Looking up breakpad interfaces from steamclient
Calling BreakpadMiniDumpSystemInit
Looking up breakpad interfaces from steamclient
Calling BreakpadMiniDumpSystemInit
Steam_SetMinidumpSteamID:  Caching Steam ID:  76561198079045666 [API loaded yes]
Steam_SetMinidumpSteamID:  Setting Steam ID:  76561198079045666
[0730/182242:ERROR:resource_bundle.cc(411)] Failed to load /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/cef_gtk.pak
Some features may not be available.
[0730/182242:WARNING:proxy_service.cc(646)] PAC support disabled because there is no system implementation
Finished uploading minidump (out-of-process): success = yes
response: CrashID=bp-3f57a49c-f31c-4a07-9330-2a8452130730
SDL video target is 'x11'
This system supports the OpenGL extension GL_EXT_framebuffer_object.
This system supports the OpenGL extension GL_EXT_framebuffer_blit.
This system supports the OpenGL extension GL_EXT_framebuffer_multisample.
This system DOES NOT support the OpenGL extension GL_APPLE_fence.
This system DOES NOT support the OpenGL extension GL_NV_fence.
This system supports the OpenGL extension GL_ARB_sync.
This system supports the OpenGL extension GL_EXT_draw_buffers2.
This system supports the OpenGL extension GL_EXT_bindable_uniform.
This system DOES NOT support the OpenGL extension GL_APPLE_flush_buffer_range.
This system supports the OpenGL extension GL_ARB_map_buffer_range.
This system supports the OpenGL extension GL_ARB_vertex_buffer_object.
This system supports the OpenGL extension GL_ARB_occlusion_query.
This system DOES NOT support the OpenGL extension GL_APPLE_texture_range.
This system DOES NOT support the OpenGL extension GL_APPLE_client_storage.
This system DOES NOT support the OpenGL extension GL_ARB_uniform_buffer.
This system supports the OpenGL extension GL_ARB_vertex_array_bgra.
This system supports the OpenGL extension GL_EXT_vertex_array_bgra.
This system supports the OpenGL extension GL_ARB_framebuffer_object.
This system DOES NOT support the OpenGL extension GL_GREMEDY_string_marker.
This system supports the OpenGL extension GL_ARB_debug_output.
This system supports the OpenGL extension GL_EXT_direct_state_access.
This system DOES NOT support the OpenGL extension GL_NV_bindless_texture.
This system supports the OpenGL extension GL_AMD_pinned_memory.
This system DOES NOT support the OpenGL extension GL_EXT_framebuffer_multisample_blit_scaled.
This system supports the OpenGL extension GL_EXT_texture_sRGB_decode.
This system DOES NOT support the OpenGL extension GL_NVX_gpu_memory_info.
This system supports the OpenGL extension GL_ATI_meminfo.
This system supports the OpenGL extension GL_EXT_texture_compression_s3tc.
This system DOES NOT support the OpenGL extension GL_EXT_texture_compression_dxt1.
This system DOES NOT support the OpenGL extension GL_ANGLE_texture_compression_dxt3.
This system DOES NOT support the OpenGL extension GL_ANGLE_texture_compression_dxt5.
This system DOES NOT support the OpenGL extension GLX_EXT_swap_control_tear.
GL_NV_bindless_texture: DISABLED
GL_AMD_pinned_memory: DISABLED
GL_EXT_texture_sRGB_decode: AVAILABLE
GL_NVX_gpu_memory_info: UNAVAILABLE
GL_ATI_meminfo: AVAILABLE
GL_ATI_meminfo: GL_TEXTURE_FREE_MEMORY_ATI: Total Free: 924030, Largest Avail: 689594, Total Aux: 1887582, Largest Aux Avail: 4096
GL_MAX_SAMPLES_EXT: 8
Did not detect any valid joysticks.
Querying for subscribed files
IDirect3DDevice9::Create: BackBufWidth: 1600, BackBufHeight: 900, D3DFMT: 3, BackBufCount: 2, MultisampleType: 2, MultisampleQuality: 0
GL sampler object usage: ENABLED
GL prefer MapBufferRange: NO
BinkOpen( /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/media/valve.bik )
ConVarRef volume doesn't point to an existing ConVar
BinkOpen( /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/media/l4d2_intro.bik )
IDirect3DDevice9::CreatePixelShader: shaderapi's centroid mask (0x0000000E) differs from mask derived from shader name (0x0000001F) for shader ps-file shadow_ps20b ps-index 1 ps-combo 0
IDirect3DDevice9::CreatePixelShader: shaderapi's centroid mask (0x000000E0) differs from mask derived from shader name (0x000000C0) for shader ps-file water_ps20b ps-index 8 ps-combo 0
IDirect3DDevice9::CreatePixelShader: shaderapi's centroid mask (0x0000000E) differs from mask derived from shader name (0x0000001F) for shader ps-file shadow_ps20b ps-index 0 ps-combo 0
IDirect3DDevice9::CreatePixelShader: shaderapi's centroid mask (0x000000E0) differs from mask derived from shader name (0x000000C0) for shader ps-file water_ps20b ps-index 1272 ps-combo 0
IDirect3DDevice9::CreatePixelShader: shaderapi's centroid mask (0x000000E0) differs from mask derived from shader name (0x000000C0) for shader ps-file water_ps20b ps-index 1272 ps-combo 1
IDirect3DALSA lib pcm.c:7339:(snd_pcm_recover) underrun occurred
Fontconfig error: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 70: non-double matrix element
Fontconfig error: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 70: non-double matrix element
Fontconfig warning: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 78: saw unknown, expected number
Looking up breakpad interfaces from steamclient
Calling BreakpadMiniDumpSystemInit
Steam_SetMinidumpSteamID:  Caching Steam ID:  76561198079045666 [API loaded yes]
Steam_SetMinidumpSteamID:  Setting Steam ID:  76561198079045666
warning: Unknown nb_ctl request:  4
warning: Unknown nb_ctl request:  4
warning: Unknown nb_ctl request:  4
warning: Unknown nb_ctl request:  4
warning: Unknown nb_ctl request:  4
warning: Unknown nb_ctl request:  4
Installing breakpad exception handler for appid(gameoverlayui)/version(1.0_client)
Installing breakpad exception handler for appid(steam)/version(1374875626_client)
Device9::CreatePixelShader: shaderapi's centroid mask (0x000000E0) differs from mask derived from shader name (0x000000C0) for shader ps-file water_ps20b ps-index 20 ps-combo 0
IDirect3DDevice9::CreatePixelShader: shaderapi's centroid mask (0x000000E0) differs from mask derived from shader name (0x000000C0) for shader ps-file water_ps20b ps-index 464 ps-combo 0
IDirect3DDevice9::CreatePixelShader: shaderapi's centroid mask (0x000000E0) differs from mask derived from shader name (0x000000C0) for shader ps-file water_ps20b ps-index 464 ps-combo 1
IDirect3DDevice9::CreatePixelShader: shaderapi's centroid mask (0x000000E0) differs from mask derived from shader name (0x000000C0) for shader ps-file water_ps20b ps-index 392 ps-combo 0
IDirect3DDevice9::CreatePixelShader: shaderapi's centroid mask (0x000000E0) differs from mask derived from shader name (0x000000C0) for shader ps-file water_ps20b ps-index 392 ps-combo 1
IDirect3DDevice9::CreatePixelShader: shaderapi's centroid mask (0x000000E0) differs from mask derived from shader name (0x000000C0) for shader ps-file water_ps20b ps-index 504 ps-combo 0
IDirect3DDevice9::CreatePixelShader: shaderapi's centroid mask (0x000000E0) differs from mask derived from shader name (0x000000C0) for shader ps-file water_ps20b ps-index 504 ps-combo 1
IDirect3DDevice9::CreatePixelShader: shaderapi's centroid mask (0x000000E0) differs from mask derived from shader name (0x000000C0) for shader ps-file water_ps20b ps-index 80 ps-combo 0
IDirect3DDevice9::CreatePixelShader: shaderapi's centroid mask (0x000000E0) differs from mask derived from shader name (0x000000C0) for shader ps-file water_ps20b ps-index 120 ps-combo 0
IDirect3DDevice9::CreatePixelShader: shaderapi's centroid mask (0x000000E0) differs from mask derived from shader name (0x000000C0) for shader ps-file water_ps20b ps-index 72 ps-combo 0
IDirect3DDevice9::CreatePixelShader: shaderapi's centroid mask (0x000000E0) differs from mask derived from shader name (0x000000C0) for shader ps-file water_ps20b ps-index 888 ps-combo 0
Loaded program cache file "glbaseshaders.cfg", total keyvalues: 738, total successfully linked: 738
Loaded program cache file "glshaders.cfg", total keyvalues: 0, total successfully linked: 0
Precache: Took 24339 ms, Vertex 1072, Pixel 870
Game.so loaded for "Left 4 Dead 2"
IDirect3DDevice9::CreatePixelShader: shaderapi's centroid mask (0x0000000E) differs from mask derived from shader name (0x0000001F) for shader ps-file shadow_ps20b ps-index 1 ps-combo 0
IDirect3DDevice9::CreatePixelShader: shaderapi's centroid mask (0x0000000E) differs from mask derived from shader name (0x0000001F) for shader ps-file shadow_ps20b ps-index 0 ps-combo 0
Unable to remove /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/textwindow_temp.html!
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/pak01_000.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/pak01_000.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/pak01_011.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/pak01_011.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/pak01_007.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/pak01_007.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/update/pak01_000.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/update/pak01_000.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/pak01_008.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/pak01_008.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2_dlc3/pak01_000.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2_dlc3/pak01_000.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2_dlc3/pak01_003.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2_dlc3/pak01_003.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2_dlc2/pak01_001.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2_dlc2/pak01_001.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2_dlc1/pak01_000.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2_dlc1/pak01_000.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2_dlc2/pak01_000.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2_dlc2/pak01_000.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/pak01_002.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/pak01_002.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/pak01_003.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/pak01_003.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/pak01_010.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/pak01_010.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/pak01_009.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/pak01_009.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/pak01_001.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/pak01_001.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/pak01_004.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/pak01_004.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/pak01_005.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/pak01_005.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/pak01_006.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/pak01_006.vpk was never closed

This time it freed itself from the freeze by killing hl2.sh the file which segfaults sometimes when entering an online game.

File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/lef/home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/./hl2.sh: Zeile 67:  2536 Getötet                ${GAME_DEBUGGER} "${GAMEROOT}"/${GAMEEXE} "$@"

So it's possibly connected with #2719

When I manage to enter a game, it freezes when I leave it, definitely during it tries to close the files at the end of the log.

Log:

Game.so loaded for "Left 4 Dead 2"
IDirect3DDevice9::CreatePixelShader: shaderapi's centroid mask (0x0000000E) differs from mask derived from shader name (0x0000001F) for shader ps-file shadow_ps20b ps-index 1 ps-combo 0
IDirect3DDevice9::CreatePixelShader: shaderapi's centroid mask (0x0000000E) differs from mask derived from shader name (0x0000001F) for shader ps-file shadow_ps20b ps-index 0 ps-combo 0
Unable to remove /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/textwindow_temp.html!
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/pak01_000.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/pak01_000.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/pak01_011.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/pak01_011.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/pak01_007.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/pak01_007.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/update/pak01_000.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/update/pak01_000.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/pak01_008.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2/pak01_008.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/left4dead2_dlc3/pak01_000.vpk was never closed
File /home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/lef/home/michael/.local/share/Steam/SteamApps/common/Left 4 Dead 2/./hl2.sh: Zeile 67:  2536 Getötet                ${GAME_DEBUGGER} "${GAMEROOT}"/${GAMEEXE} "$@"
Game removed: AppID 550 "Left 4 Dead 2 (Beta)", ProcID 2536 

I haven't played L4D2 in a while (1 year) so can't tell.