Hey,

when playing Left 4 Dead 2 (only thing I tested) for a long time, the system
randomly hangs. Happens maybe once an hour or so. I think it's not only X that
crashes, but the whole kernel. Can't do sysrq, poweroff, restart..

I upgraded to the testing 3.13 kernel in archlinux, that's when I experienced
it the first time. So I reverted back to 3.12 and everything was fine again.
Now that 3.13 hit the core/stable repo I gave it another try and it started
crashing again.

linux 3.13.4 (also 3.13, 3.13.1, 3.13.2 <- I'm not sure if it happened with all
of these, but most likely it did )
ati hd 5850 (Cypress PRO)
mesa-git - r600g ( Mesa 10.2.0-devel (git-9b2fe7c) )

dpm was also manually enabled with 3.12 and before, so it's likely not related
to that. Never had problems with it.