GeForce 8600GT 256MB 10.5.7

[iSam24]

Okey so i installed 10.5.7 iAKTOS and everything is fine i enabled my video card (8600GT 256MB) via EFI Enabler in OSX86Tools but when i change my reslution i get a plain blue screen so i rebooted and i had max resolution... but when i play games in full screen mode fior example Halo, SIMS 3 i just get a black screen... but if i play halo in a window it plays perfect... and also when i minimize a quicktime movie i dont get a preview in the dock... but i have a transparent menubar and Quartz Extreme and GL enabled... any help guys ???? thanx in advice ;P

BTW its a Galaxy GeForce 8600GT 256MB Overclocked also its connected to a 17 inch monitor via VGA i get 1280x1024 at 75Mhz