I have just built a new computer from parts. Whenever I resume from any sleep mode (S1, S3 or S4) the computer freezes within about 60 seconds of the welcome screen appearing.

I have updated the BIOS and all drivers to current from the motherboard manufacturer's site. I have reset BIOS settings to default, including disabling AMD Cool n Quiet.

The windows event logs are not helpful at all. Other than immediately after resuming the system is stable as long as AMD CnQ is disabled.

The system is:

Mobo       : MSI 790GX-G65
CPU        : AMD Phenom II 965 BE at 3.6 GHz
Memory     : Corsair DDR3 1600, at 1333 MHz and 9-9-9-21
HDDs       : 1 EIDE, 2 SATA in RAID-0
DVD        : 1 
Card Reader: 1 multi-card reader

Keyboard is attached via PS2 and mouse is USB.

Any thoughts or pointers would be most welcome.

EDIT: It appears that the computer may not freeze if a program is left running which puts it under significant load. I left a stress test running which keeps all cores under 85% load, and my son put the computer to sleep - while this program is running it I have been able to resume from S3 successfully 4 times, compared against about 20 tests with the computer idle which have all frozen. So this may be related to being in an idle state when it resumes.