I don't have your mobo and am not that familiar with overclocking 2gb sticks but it seems to me that your northbridge is a bit low (most run 1.4-1.55) and definitely your ram - ddr2 ram at least for the 1gb sticks need 2.2v usually for that fsb. Of course lock pci-e to 100 and turn off eist/speedstep, etc.