@Yopale - Very interesting, same thing here, no problem with -x32 flag.

In a couple of days I'm gonna get my hands on a 8800GT w/512mb to try and see if that resolves the problem. I know of someone running SL with an 8800GT who isn't having this problem.

Edit:
I had a brain fart, when i said no prob with -x32, I meant -x (safe mode). When I tried the -x32 flag, I wasn't able to actually get into 32 bit mode. I had to change the kernel flag in com.apple.Boot.plist to arch=i386, then run KextUtility, then after reboot I was in 32bit mode. I haven't had a KP since. Thanks for the tip Yopale.

On a side note about 32bit mode. I was never able to access my Windows partitions in x64 mode connected via ATA port. My other drives are all SATA, maybe jmicronATA.kext isn't being loaded, but with x32 mode all of my ntfs partitions are now accessible. At least I can see which extensions are 32bit by looking at the loaded extensions in System Profiler.

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System 1: Gigabyte GA-P35-DS4 MB with Intel e6750 Core 2 Duo w/8 GB RAM (Retail install)
GeForce 8800GT 512MB, Snow Leopard 10.6.2
System 2: Dell Optiplex GX280, Intel P4 3.0Ghz w/3GB RAM
GeForce 7800GTX 256 MB, Leopard 10.5.7 using iATKOS v.7 install (work in progress)