Hardware problem

Been having a problem for a few weeks now that I've been struggling to resolve. After a crash one night it came up with a bad bios checksum error.
I couldn't get the bios recovery tool to work, so started to rma parts.

So far I've rma'ed the power supply, and the motherboard, when i talked to a tech at asus they seemed fairly sure that it was the motherboard still, so they issued me another rma and sent me a shipping label.

Most recently, i was able to get the bios recovery tool to recognize the bios and it erased the old one and reprogrammed it, and then it would still come up with a bad bios checksum error again, as many times as i did it and i'm trying to figure out what the problem is before sending more stuff out. One problem with this is I don't have any spare hardware around or know anyone locally who does.

The hardware in question is an asus p5q pro motherboard, e8400 cpu, 2x2gb gskill ram, ati 4850 and a pcp&c silencer 610psu.

If anyone could give me some ideas would be greatly appreciated.
Thank you~

Check the voltage on the motherboard battery.

I Think i checked it, but.. i might have forgotten to. Can't check it now since i Just sent it off.

This issue occurs on the new motherboard? Or you have not RMAed it yet.

If you have not RMAed, than get to it

EDIT: I type too slow

Yes, the motherboard just got sent out for the second time.

have u tried taking one stick of ram out and trying them one at a time? if not I'd try that when the new mobo comes in if you are still having a problem. if that doesnt help try running memtest, not sure if you will be able to but worth a try. if its not the ram then I would lean more heavily toward the hdd rather than the vidcard.

I did try one stick at a time, and each one in different slots, can't run memtest as it doesn't post.