I faced some strange problem. My system is D425KT installed into Thermaltake Element Q chassis (http://www.thermaltake.com/products-model.aspx?id=C_00001514) with two 2 GB 1066 MHz DDR-3 memory modules from Kingston (http://www.cmtlabs.com/mbTestSummary.asp?bNav=True&sTestNum=018150). When the system is running and I shut it down, the system powers down, but after 2-3 seconds it reboots by itself and starts loading again. It doesn't matter whether I turn the system off by means of the power button on the chassis or by means of the installed OS. The system shuts down, waits for 2-3 seconds and then starts loading again. The only way to power it down without reboot following is to hold power switch button for more than 4 seconds.
Of course all the wake up settings are set to "Stay Off" in BIOS. The only things connected to the motherboard are the PSU, power switch and USB keyboard.
Updating from original BIOS (0083) to latest (0113) didn't solve the problem. By the way, I was able to to update the BIOS only by placing motherboard jumper into recovery mode. When I tried to update the BIOS from normal mode using IFLASH2.exe utility, it just rebooted the system and did nothing.
I believe this to be some hardware issue. Should I call my distributor for a replacement?
You can test the system out of the case in order to make sure this behavior is not due to a grounding conflict; other than this, you may try clearing CMOS before performing a BIOS Recovery.
Clearing CMOS instructions can be found here: http://www.intel.com/cd/channel/reseller/emea/eng/membership/411560.htm
If none of these work, you may contact your distributor for warranty assistance if within 30 days. Else, you may contact Intel(R) Customer Support which can be contacted at: http://www.intel.com/p/en_US/support/contact/phone