Hi!

First off, my hardware:

Gigabyte EP45-UD3R
Intel Quad Core Q8400
RAM: 4GB DDR2
Gigabyte GeForce 9600 GT Silent 512MB
1 TB WD IntelliSpeed SATA HDD
OptiArc SATA DVD-RW
Nexus 430W Ultra Silent PSU

Secondly, my installation:
Vanilla OSX 10.5.7 installed of retail 10.5.6 and updated via software update.

This is what I've got working:
Sound (kext),
Ethernet with bonjour (kext),
Sleep ,
Shutdown/Restart (kext),
QE/CI (via EFI string)
Time Machine (via EFI String)

So, everything seems to be running fine, BUT:

When I try to access my Applications stack, in grid mode, my screen freezes. Sometimes I can get as far as to get it open, but when I close the stack, the system freezes.

This does NOT occur when I boot without QE/CI enabled (without the EFI string). OpenGL Extension viewer tells me that everything is OK, and all the tests I throw at my system in QE/CI mode get a green light.

Any ideas would be highly appreciated. Tell me if I left out something vital.

Thank you!