Please test a bleeding edge version of mesa, perhaps from oibaf or xorg-edgers ppa, if the problem persists, then this should also be reported to the mesa devs.
Thanks for your response.
I installed the oibaf ppa and played in single mode for ~2 hours without any hang or crash.
The latest code seems to have fixed the problem.
Reverted back to official ubuntu packages (mesa 10.3.2).
Working fine for now.
Nothing extracted yet.
I've been facing this issue for the past 2 months.
Sometimes the game runs smoothly for 3-4 hours without any hitch. But recently it just hangs within 5 minutes after starting the game.
It happens in both offline and online mode.
System Information: