Trying for the Lambda Locator achievement by following a Youtube guide, when I come to cache number 17 the Lambda graffiti is missing, see screen below.

The shot below is from the Youtube video showing how it should appear.

Processor Information:
Vendor: GenuineIntel
Speed: 3501 Mhz
8 logical processors
4 physical processors
HyperThreading: Supported
FCMOV: Supported
SSE2: Supported
SSE3: Supported
SSSE3: Supported
SSE4a: Unsupported
SSE41: Supported
SSE42: Supported

Network Information:
Network Speed:

Operating System Version:
Ubuntu 12.10 (64 bit)
Kernel Name: Linux
Kernel Version: 3.7.0-7-generic
X Server Vendor: The X.Org Foundation
X Server Release: 11304000
X Window Manager: Xfwm4
Steam Runtime Version: steam-runtime-release-i386_2013-05-08

Video Card:
Driver: NVIDIA Corporation GeForce GTX 560 Ti/PCIe/SSE2

Driver Version:  4.3.0 NVIDIA 319.23
Desktop Color Depth: 24 bits per pixel
Monitor Refresh Rate: 59 Hz
VendorID:  0x10de
DeviceID:  0x1200
Number of Monitors:  1
Number of Logical Video Cards:  1
Primary Display Resolution:  1920 x 1200
Desktop Resolution: 1920 x 1200
Primary Display Size: 20,39" x 12,76"  (24,02" diag)
                                        51,8cm x 32,4cm  (61,0cm diag)
Primary Bus: PCI Express 16x
Primary VRAM: 1024 MB
Supported MSAA Modes:  2x 4x 8x 16x 

Sound card:
Audio device: Realtek ALC892

Memory:
RAM: 16005 Mb

Miscellaneous:
UI Language: English
LANG: en_GB.UTF-8
Microphone: Not set
Total Hard Disk Space Available: 938898 Mb
Largest Free Hard Disk Block: 811830 Mb

Installed software:

Recent Failure Reports: