Built new system, but having a problem I can't seem to permanently fix.

[Underhanded]

Now, I don't exactly know whats going on here, but If you need the specs of my new rig, they are in my Signature.
Ok, so this is how it goes down. I have my AMD Athlon 64 4000+ overclocked to 2.6 from 2.4 (minor 10%) increase, I also have my 7800GT OC'd from 450mhz to 470 (Was 485 before, JUST lowered it). The problem is, when I start up my computer, it boots up just fine but when it gets to the desktop and starts loading my antivirus software (NOD32), it shuts down and restarts. The screen goes black, and it returns me to the enter setup screen.
At first I thought it could be a hard drive problem, so I ran the disk scanner I got off the Seagate website, it came up with no errors. When I reset the motherboard (CMOS jumper) It boots up just fine and stays on indefinatly (Which is how I'm writing this). I took the overclock off my Processor, as I thought maybe it was overheating (though the heatsink fan combo (stock) was quite cool, and the bios reported it as running at 35C. Perhaps it was the graphics card overclock, that was a bit hotter at 55-60C average (stock cooler), so I have retuned it to its unoverclocked state. This rig was working beautifully in the past, no problems at all. I've been having this problem for a week or so, and am not entirely sure what I can do to fix it. It seems that when I reset the time/date to the correct time, the problem occurs again and I have to reset the BIOS, I don't think, however, that this is the problem.
I'm going to try restaring it now that my GPU is not overclocked, in the meantime, I would appreciate any feedback you guys might have to offer. I know you're much more experienced with this,
Thank you very much.

[Underhanded]

****Update****
Removing the graphics card overclock did not fix the problem, had to reset CMOS jumper again.

[glc]

Have you tried running Memtest86+ on your ram yet? Perhaps a bios flash to a newer version may help too.

[Underhanded]

I'll give it a shot~ Thanks Glc. Will update with results when they are done.

[Underhanded]

Memtest 86 completed, no errors found.
I only ran the test once, but yeah.
Flashing the bios makes me nervous ^^; There isn't an executable to do it from the asus website, and booting from floppy and flashing there always made me nervous. Is there any other solution you might suggest? I'm going to update the chipset drivers first.. See if that helps.

[jayb1234]

You could buy a new bios chip with the new version already on it.

[nosefirst]

Flash it off your desktop if you don't like the floppy.