Motherboard is GA P45 UD3, with Q9550.
I'm using a USB stick to boot a RAID 0 on WD Eco Blue 500GB drives. On this USB, I have Chameleon RC2, and mkext with:

Disabler.kext
IOAHCIBlockStorageInjector.kext
NullCPUPowerManagement.kext
OpenHaltRestart.kext
PlatformUUID.kext
SleepEnabler.kext
fakesmc.kext

Disabled APM on my hard drives. Also unchecked to sleep disks in system preferences.
I can't give further information, because nothing is written in dmesg when this happens...