http://bugs.winehq.org/show_bug.cgi?id=35847
--- Comment #6 from DL dredgingthelake@gmail.com --- I ran some more tests. Setting VRAM to 4095 or 4098 = no problems. But setting to 4096 or 4097 results in out of memory errors.
Also, setting to 4096 using the registry key instead of within the code doesn't result in the error, but 4097 does. So there's some specific amount of vram that causes problems.