I switched back to BIOS mode yesterday. (reformated and did a clean reinstall of gentoo + windows) (ofcourse, I did make backups
The driver 290.10 works so far.
I didnt test the driver 295.20, yet.
PS: Windows 7 boots faster in BIOS mode
//edit: Using uvesafb with 2560x1600-32@60.
When I boot with UEFI and efifb only 800x600 is possible. Other resolutions are mac only?!