http://bugs.winehq.org/show_bug.cgi?id=23096
--- Comment #6 from Anton olaf_nz@hotmail.com 2010-07-31 00:20:40 --- I have just upgraded to an Nvidia GTS250 and the problem has completely disappeared for me. All other system settings are identical except for running off the proprietary Nvidia drivers rather than the ATI Radeon drivers.