Some back ground on the MB.
It uses the VIA KT400 chipset which has certain limitations. The KT400, un like the NF2 chipset, can not "lock" the AGP and PCI bus speeds. Due to that as you up the CPU's FSB the PCI/AGP buses also increase and if it gets to excessive will cause instability.
Our FAQ section is undergoing a major transfer and temporaraly a bit of a can of worms
There are some How To faqs on OCing basics.
Some good one to read
More on the "Lock"
A very good guide...
Also, by using the "USER CP" at the top of the page you can link to "System Specs", filling them can be very useful for the members to refer to you system when giving advice.