some slight problems - not sure whats causing

obviously been tinkering with the ol' overclock recently and have cause a few problems with my system......

this all seemed to occur after i bumped my core voltage up to 1.5v and the NB voltage to +0.2 trying to hit 3.5GHz. system wasn't orthos stable and caused a reset of my bios. the below problems began to occur.

1. System won't boot when you first press the power button. the system will be powered as the fans are all going, but it won't even make it to the post.

2. The system will work when you press the restart button.

then, i proceeded to overclock at lower ranges, thinking that this might have something to do with the instablilty. i went for a 3.1GHz with 1.45V core and +.1 MCH. this was 10 hours orthos stable before i decided to up it again trying to hit 3.3GHz with 1.5V. this next problem now occurs

3. It won't work when you have attepted an overclock, ie. upped the FSB or any of the voltages. it will reset itself again, and return with the manual settings overwritten with AUTO. BIOS has not reset to default values but they are all set to AUTO in the MIT settings page.

any help would be sweet. have i damaged my Northbrige with a touch too much voltage? or is something else on my MB damaged, cause this behaviour isn't normal.

Elaborate on your system specs in the signature. For example, how many GB and what configuration of ram are you running? OS?

Remove the Mobo Battery and wait ~10mins. Then boot back into bios and see if it's at factory defaults. After that, I can't help you much because I have no experience with your chipset or CPU. It simply sounds like your CPU doesn't like those high frequencies or the voltages that come with them. And I don't think that small bump in NB voltage would fry anything.

i've reset the mobo using the jumpers. didn't doo much.

funning the latest 13i bios

the ram is 2x1GB which passed 16 memtest runs without an error. its also brand new and running under rated speeds. i've got my old stuff which i might have to try.
OS is XP Pro SP2

6HDD of varying specs. few WD, a few Seagate and a Samsung.

2 Optical.

2x 19WS Monitors

Logitech Wireless mouse and keyboard.