This sounds you might have a cooling issue. Make sure you have good contact between yuo heatsink and the CPU..also try using some thermal grease (i.e. artic silver) Never hurts to put in another case fan directing air over the heat sink as well. If you are trying to over clock it then you also have to make sure that your RAM can support it. Ive got the same setup as you do but with a 3.6 ghz and a x700 pro video card.
My overclocking experience with this board is that it is somewhat unstable when overclocking it
Hope this helps
