http://bugs.winehq.org/show_bug.cgi?id=31406
--- Comment #5 from Henri Verbeet hverbeet@gmail.com 2012-08-19 07:15:00 CDT --- (In reply to comment #4)
Using Fedora 14 with a radeon R600: OpenGL vendor string: Advanced Micro Devices, Inc. OpenGL renderer string: Mesa DRI R600 (RV710 954F) 20090101 TCL DRI2
You want to be using fairly current versions of r600g, but that's probably not the issue here.
My guess would be that this an issue with libX11 over XCB and not necessarily specific to a particular driver (but still technically UPSTREAM). It may be interesting to see if it works any better with a libX11 built with --without-xcb, although I could also very well imagine all kinds of things depending on being able to mix XLib and XCB at this point.
You may also want to try to simplify that test case a bit more and port it to pure GLX / XLib.