One day it works, and the next day it doesn't

I?ve had lots of different things cause weird problems like or similar to this so I?ll run down the list:
-Bad caps, usually this becomes progressively worse. Look for capacitors with rounded tops; they should be perfectly flat.

-Bad memory modules, replace with a known good if you have them or pull modules out one by one if you don?t. The idea is that the odds of all your modules are bad is small, pulling them out and then insert them one by one in reverse order can isolate the one bad module. The only problem is if you only have one module or if your motherboard needs a matched pair to run.

-Defective processor, not much you can do to test this unless you have another motherboard that can accommodate the processor or if you have another processor.

-Cold solder joints on components or cracked circuit board runs on the motherboard.

-Power supply with inconsistent voltages.

-Grounding, hard to mess up since the screws you use to mount the motherboard connect are what ground it to the chassis. The holes the screws pass through have exposed copper on the top edges, the heads of the steel screws make contact with the exposed copper and ground it direct to the chassis. Incidentally just in case it needs to be said you shouldn?t use insulating washers on the mounting screws unless the MB manufacturer says to.

-Assembly issues: with boards as tight as they are not its possible that you might have bent a capacitor while installing the processor fan mount or perhaps have a MB mounting screw touching a capacitor or other device lead.

If none of this works and if your board is still under warranty I would get back on the phone and demand a warranty replacement. Chipset drivers load after Windows start, not during the initial boot sequence. You?ve already checked for grounding issues so you can rule that out. Even if it is a BIOS problem you?ve already flashed the BIOS which is way more than I would have ordinarily done for a new board with problems out of the box.

Let us know what the outcome is?.

you know i had on of these from a compaq that they made for them and
sometimes i could get it to reset and sometimes not
strangest motherboard i ever saw
i kept crashing the backup battery to get it to post
i think the bios is wrong on it and needs to be reflashed
at that point i would buy mother board with that footprint
asus site has all the exec files for that model number

Well thank you for the suggestions. As it turns out, my power supply was showing voltages around 2.6V-2.7V rather than the 3.3V it was supposed to be putting out. So being that it was like 7 years old, it didn't surprize me. So I got a new one and installed it. After some problems on my part of reversing the drive boot order in my BIOS by accident (the machine would simply reboot just before Windows XP stated to load). The machine seems to be working very well and reboots fine everytime. Thanks again.