If you're going to purchase a new motherboard go for an asus, i've got an asus m2a-vm which is great for overclocking amd chip's. I currently have my 3800+ running (for the last year) at 2.7 (2.4 default) and it hasn't fallen over yet ! Also, good cooling is a 'must have'. Just make sure you increase the fsb in small increments.
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(amd athlon 64 3800+, freezer 64 pro, m2a-vm, geforce 8600gt 512 super, 2gb pc2-6400 ram ddr2 800, 450 watt psu