I have the deluxe 1702 BIOS, and no matter what I do, 500fsb wont work. High 490s is fine.
Used up to 1.4vcore (1.365 is fine for 490)
Up to 1.3 VTT
GTL refs to .67 each
PLL at 1.58-1.6
NB up to 1.3

My ram is good up to 1070ish with stock volts and timings, so its not them.

Also, I am having boot issues, even at stock, where it will come on, but wont display an image, untill I restart it a hundred times and randomly get lucky. And I know the 280 is fine, it doesnt artifact at all, and runs in the 50c range idle, high 60s load.