Restarts, freezing, BIOS Settings reset

[nield]

Lo all, I got computer problems

system details:

Gigabyte GA-965P-DS3 (F10 BIOS)
Core2duo E6300
2GB PC6400 800Mhz DDR2 RAM
HIS ATI Radeon X1950 Pro ICEQ3 256MB

Nothing is overclocked atm.
BIOS, drivers are all up to date.

The problems are:

Random freezing and restarts
Not starting up again after the restarts (Not posting)
BIOS settings resetting


I have tryed a different video card , no luck.
I have run a ram test and it found one of the sticks faulty so I removed it, current 1gb stick has been tested on its own and has no faults. (RMA'ing both tomorrow)
I have tryed formatting both current hard drive and also a different hard drive, no luck.
I have tryed unplugging all CD/DVD drives, PCI cards and having only the essensial stuff plugged in, no luck.

I did infact only flash to the latest BIOS this morning, the computer ran perfectly all day with no problems, then just now froze and restart, reset the bios settings.

I have read it might be a problem with my CMOS battery, im going to get a voltmeter to test it tomorrow.

Any ideas?

Some more info on when it doesnt POST, all of the systems/video/cpu fans come on, the CD/DVD drives and hard drive lights all flash, the monitor stays off as if its not getting a signal.

Some more info, i fails to boot for a short amount of time after it crashes or I have to force restart it either by holding down the power button for afew seconds or by the pressing the reset button.