http://bugs.winehq.org/show_bug.cgi?id=7015
------- Additional Comments From xerox_xerox2000@yahoo.co.uk 2007-02-01 18:19 ------- A little update: (so Thunderbird won't forget this bug ;))
From the MSDN page:
If any of the following flags are set, ChoosePixelFormat attempts to match pixel formats that also have that flag or flags set. Otherwise, it attempts to match pixel formats without that flag set:
PFD_DOUBLEBUFFER PFD_STEREO
So that's exactly what's the problem in this bug. I'll await the fix ;)