SL-75FRN2-RL voltage trouble...

For the past few weeks I've been very happy with this board. I had my athlon xp 1700 running at 2 ghz (11 x 182), but I decided to stop there until my 2 sticks of PC3200 and new heatsink arrived. The package came last thursday, so I put in the new memory, swapped in the new heatsink, and, having heard that it would possibly provide extra stability, applied some arctic silver between the northbridge and its heatsink. Feeling quite confident that I would be able to get a much higher overclock, I booted the computer up, and began working my way back up to where I had been. This is where the trouble started...whenever I increased the cpu voltage past the default, the screen would become garbled after displaying the windows loading screen, and the computer would reboot. And if I tried to go into the BIOS to fix the problem, the computer would also reboot. Right now I'm running fine at all the defaults, but I didn't buy all this new stuff for that! I've tried changing the memory, power supply, cpu, and even the case, but I can't seem to solve the problem. I've considered sending the motherboard back in for repair/replacement, but I'm sure I must've voided the warranty by messing with the northbridge. Does anyone know what the problem might be?

arctic silver 3 transfers electricity make sure
you didnt bridge any contacts with it.did you
have the cpu voltage up past default before?
also the solteks need more nb volts to oc than
the other nf2s try the middle setting on nb v
also is your cpu thA or thB. DLT3C or DUT3C
A is low volt B is high volt,ive seen others not
able to raise vcore on 1700 dlt3c certain steppings
1.6-1.675 didnt work but 1.725 did and away they
went