Shutdown problems on A8N32SLI Deluxe

[FSH42NA]

My new computer build is driving me nutso. Intermittently my computer will just go into a rebooting loop when I shutdown. Here are my specs:

ASUS A8N32 SLI Deluxe; Bios 903 (same prob with 1009)
X2 3800 (mild oc to 2200mhz)
2 x 1gb OCZ PC3200 Platinum
MSI 6600GT x 2 in SLI
Samsung 200gb SATA x 3 (non-raid)
Benq 1640 pri. master; LG 4163 sec. master
Onboard sound
Enermax 600w Noisetaker ps
XP pro w/ sp2 slipstreamed
Lian Li PC65

My memory has been tested with Memtest on both this board and the ASUS A8N sli platinum with no errors (probably a total of 30 loops at various oc settings). The drives have been tested with the Samsung diagnostic utility. I've run Prime 95 overnight. Short of a bad mobo, the only thing I can think of is the power supply or my memory settings. Recommended settings for memory with this mobo have been difficult to find, but I did find some info over at bleedinedge.com :http://www.bleedinedge.com/forum/showthread.php?t=16547&highlight=guldur

Anyways, please chime in with any thoughts or advice on what it sounds like the source of my problem is.

Thanks in advance for your replies

 

[Kenai]

Here is a thread on the forum that discusses problems with ACPI complience that casues reboots you describe:
Some fixes in there:

http://www.hardforum.com/showthread.php?t=994465

 

[FSH42NA]

Kenai,

thanks for the response. I've already visited that forum (I'm "fsh42na" there also). However, the people there seem to have issues installing their OS on the Nvidia sata controller. I didn't have any problems installing the OS. On the other hand, maybe my install isn't as glitch free as I'm thinking. Maybe there is a corrupted file or two that is causing my problem. I don't "think" I'm having any ACPI issues since I didn't get any such error messages during my install. OCZ tech has given me some rec'd memory timings so I'll probably make those settings and reinstall the OS/ reflash the bios (though not in this order) and see what happens.