http://bugs.winehq.org/show_bug.cgi?id=20053
--- Comment #41 from DL taedium_vitae@eml.cc 2010-05-10 00:33:16 --- It just seems to be an issue with HL2 : EP2; it doesn't occur with any of the other HL2 games, nor does it occur with portal. I'll have to get around to installing TF2 and CS:S to see if it is EP2 specific.
I tested EP2 in native windows as well, BTW, and it works fine. So it's not a corrupted installation.