I just bought a new system with these elements

P35-DS3L, rev 2.0, F7
E2160 @ 1.80 ghz (stock)
2 x 2048 DDR2 PC2-6400 Corsair XMS, 5-5-5-18, 1.8v
HD 4850

It worked fine for the first boot, then when I rebooted it said

Award Boot Block BIOS V1.0

Scanning BIOS Image in Hard Drive

Auto-recovering...

After that it just repeats. So I tried clearing the CMOS with a jumper on the reset pins - didn't work

So I just thought I had a faulty bios. But here's where it begins to get odd and the reason why I haven't RMA'ed it yet, and this is where I hope someone can help.

I had 2 spare PC2-5400 Kingston ram, and I plugged them in, it said the auto-recovering once and booted up fine, so I installed windows and it worked fine. So I thought it was the CRS rams that was faulty, so I checked and plugged them in again, and it booted fine, even booted windows and it worked great, even under stress. On the next reboot it starts the same endless cycle with Auto-recovering (I can then insert the kingston and it'll work again). So I tested the CRS with memtest86+ for 24 hours and the odd thing is that there's no errors on either of the blocks.

So I'm baffled, is it the rams I should RMA or the board?

Gigabyte boards seem to die an endless power cycling death these days. I have one on RMA.

Before you rma, are you ok with flashing the bios? Look for a stable bios and flash to it with a usb drive. Look at the manual for how to flash bios with the built-in one. I think it's ALT F2 or in the bios menu. F8 is the latest, but the description says it updates cpu microcodes. Flashing bios for your cpu may be irrelevant.

Try upping the vdimm to 1.9v and reproducing the same symptom. If no luck, 2.0v. Up to 2.1v. If that still won't fix it, rma the mobo & ram.

@OP: Your BIOS is corrupted. Get a new BIOS image from the website and re-flash the BIOS.

aha, it worked with reflashing the bios - always a joy when everything eventually works like it should. Thanks for the help both of you!