https://bugs.freedesktop.org/show_bug.cgi?id=36421
--- Comment #4 from Tobias Jakobi liquid.acid@gmx.net 2011-05-01 04:02:42 PDT --- This seems to be a problem with all games that use the HL2 engine in its DX9 level mode. Portal seems to force dxlevel >= 90 and therefore always produces this lockups.