So I just bought a 1GB DDR2 PC2-5300 stick of the PNY brand to replace my old 512's. When I took out the old sticks and plugged in the PNY the PC would not boot. It would just infinitely power itself on and then off again until I pulled the plug. Put the 512's in again and it works fine. The PNY stick says it is compatible with 667MHz, 533 MHz, and 400MHz so I doubt that is the issue as the 512's are 533MHz. Could PNY just be plain non-compatible with this board?