Has anyone else encountered this problem? I have a pretty typical hackintosh setup. FCS 2 runs fine, the only problem is that FCP will crash while rendering - the hard crash that throws up a gray screen and tells you to hard reboot.

This happens while trying to just render clips for playback and while exporting a quicktime movie.

Compressor seems to render fine without crashing. Any thoughts? Anyone else seen this? Do you think its codec specific?

I have the exact same problem and it's driving me nuts.
Since my Leo install is on a PATA drive, I've tried disabling AppleNForceATA.kext, so I don't think that's the culprit. I don't get the kernel panic screen, just a completely frozen system ~30% through Export to Quicktime.

I was having Kernel Panics and/or program crashes during the following processes:
iDVD 08, while saving as disk image. The error would occur near the end of the "multiplexing" stage
QT, while exporting Movie to ipod video

I don't remember if FCP was crashing as well since I don't use it all that much.

My Hackintosh had 4Gb of 800mhz ram and I read somewhere to pull out 1Gb of ram to solve the problem. I did and all issues were resolved when running 3Gb.
I have since bumped up to 8Gb (2Gb x 4) and am back to crashing with QT export and iDVD. My next trick will be to replace one of the 2Gb sticks with a 1Gb, leaving 7Gb. If that doesn't fix it then maybe I'll drop back down to 3Gb.
Frankly, for what I am doing, I didn't notice much of a performance difference running 8Bg, especially if it takes a crap with more ram installed.

maybe your ram is bad since changing the amount seem to fix it, try memtest 86 and check the ram it's a bootable CD.