I have iPC PPF5 updated to 10.5.7 on my desktop. I can't do anything extraneous on it like copy 200MB. Or write code for the iPhone that has a slight bug in it. It doesn't like me multitasking or doing "big" tasks. When I do, I get the pin wheel and I'm forced to restart via power switch on the case.

My Specs are:
CPU: Intel Core 2 Quad Q6600 2.4GHz OC'd 3.2GHz
GPU: EVGA 9800GX2 SSC
RAM: 6GB Corsair XMS2 DDR2 800
HDD: Western Digital 500GB and 1TB
MOBO: EVGA 780i SLI

I have the Voodoo Kernal from the iPC installer, ApplenForceATA drivers for my nForce hardware, and the Chameleon loader [this from memory].

Any ideas? It's quite difficult to work with if I can't really multitask.