I have four two gb sticks in all slots right now for a total of eight running at 1333. I have the voltage how it was out of the box running at 1.5 volts. I ran memtest and none of the sticks seem defective but I reseated them all anyway. Everything is set to auto in the bios I havent had the chance to run stable let alone start to want to change any settings.
I did have corsair previously which did have a defective stick when the problem first appeared but even after changing to the new pny sticks which so far have passed memtest. I have seen others say after raising the voltage to 1.6 it could fix it but im sketchy on that. I have swapped everything out in this machine at least once in desperation including mobo.