Yeah I have read many similar posts of this problem, and its very disheartening. Unfortunately, no one seems to be having the same problem as me! The stability issues that they are having (general freezes in 3d mode); I resolved by changing AGP voltage / enabling USWC in BIOS. But the hang on post thing, I have not been able to fix (without pulling the card and putting another brand in there..)

I'll post there as well.. But I have decided to return my P4G8X and get a MSI Granite Bay board, and see if I have any better luck with that. Hopefully I will... Or maybe I will be worse off..