https://bugs.freedesktop.org/show_bug.cgi?id=35051
--- Comment #10 from Tobias Jakobi liquid.acid@gmx.net 2011-05-16 05:54:40 PDT --- I'm pretty sure you're seeing the common GPU reset problems when using the HL2 engine DX9 renderpath. So yes, that's the bug #36421 you already mentioned.