Hey guys, bit of a problem here. I recently bought an MSI GTX 465 Twin Frozr II Gold Edition off a fellow in Florida. The Gold Editions are pretty much guaranteed to unlock and he had his running stable. Since I got it I've had nothing but problems with it, but finally today I was able to be furmark stable, at least for 10 minutes before I closed it.

See, it crashes at stock clocks/voltage, but after I overclocked it and ran it in furmark it was stable. I was excited until I realized that the Core/Shaders were downclocking to 405/810 speeds. Memory overclock stayed at 1700 mhz. Does anyone have any ideas why this is happening? Or how I could fix it?
Edit: I reverted back to stock clocks. Furmark and GPU-Z are showing the stock clocks, while CPU-Z and MSI Afterburner show the underclocked speeds.