Very strange problem with ATI 4870 + 10.6.5

[yoyo120]

Hello,

 

I recently updated my Hacktintosh from 10.6.3 to 10.6.5, and am getting some very strange behaviour from my Sapphire 1GB 4870 Vapor-X. Since I've read that the vanilla drivers / framebuffer are now compatible with the 4870, I left ATI4800Controller.kext, ATIFramebuffer.kext, and ATISupport.kext untouched, and simply turned on GraphicsEnabler=Yes in com.apple.plist. I am using PC-EFI 10.6.

 

As expected, everything worked fine; full QE/CI and full res .... but only for one boot. The next time I rebooted, I got video corruption upon entering the OS. I tried booting with the caches ignored, but no dice. I then tried booting into safe mode and rebuilding the kext caches, but still nothing. Finally, I booted into safe mode, turned off GraphicsEnabler from com.apple.plist, and decided to revert back to ATY_Init.kext. I rebooted (normally), and everything worked fine ... for one boot.

 

After more than a dozen or so tries using different combinations, I've come to the conclusion that the only way I can get the system to boot into the normal OS is to first boot into safe mode, and then toggle from either using GraphicsEnabler=Yes + no ATY_Init.kext, or GraphicsEnabler=No and using ATY_Init.kext. It doesn't matter which of the two it is, as long as its been toggled from the other state. That is, using GraphicsEnabler=Yes twice in a row will fail, using ATY_Init.kext twice in a row will fail, but somehow switching from one to the other (whichever that may be), will result in a successful boot.

 

Also, this toggling must be done in safe-mode only. Changing between the methods while in a successful boot (normal OS) will still result in failure for the next boot.

 

Also, for the record this card has worked fine for many updates from 10.5 - 10.6.3.

 

Does anyone have any clue as to why this may be happening? Any help would be greatly appreciated.