WTF? I can hit 992.9 mhz fsb, but not 1ghz?

What's happening?

Ok, I thought my northbridge was overheating so I put a fan on there.

When I overclock I can hit 992.9 mhz front side bus, but if i do exactly 1 ghz or over the computer crashes. I have a nice cpu fan, heatsink on the southbridge, and big heatsink plus fan on the northbridge.

Anyone have any ideas??

This sucks, I have a p4 2.6c which i hear all kinds of people overclocking to 3.4 or even 3.6 and i can't even hit 3.25. (I'm at 3.227ghz). When I try, Windows XP Pro boots up and runs for about 20 seconds, then video gets weird, then it crashes (reboots).

PLEASE HELP!

Why is the 1ghz barrier the problem? BTW, I already locked my agp/pci at 33/66/100.

My specs are in my sig. People with cheaper boards than mine are able to get higher fsb overclocks than me and they also have passive cooling on the northbridge. Arghh!

did you up the voltage at all? (vcore)

My 2.6C need 1.6v to run 250FSB and you need pretty good cooling also.

Yeah, I upped the vcore and I have excellent cooling (spark 7+).

I think its an AGP issue because sometimes the video acts weird right before it shuts down.

thats what always gives me the first sign of problems also.