**** I guess I just got a non unlockable card
. The reason the agp ones can sometimes be unlocked is because they use the nv40 gpu which has 16 pipelines. Sometimes the pipelines are just messed up so they throw the chips into a 6800nu or a 6800gs. The good ones go into 6800gt or 6800ultra. They sometimes have too many of one type so will throw a good one into a gs, which is why it can then be unlocked. However mine cant I guess since they appear to be physicly damaged. Overall though the 6800gs PCIE is better because it clocks much higher.
Edit: My card idles at 52 degrees celcius, is that good or bad for a 6 series card? I will probably overclock it once I get a fan that sits below the card, see if I can break 5k in 3dmark. Not being able to unlock those pipelines really bugs me, seems like I always have the worst luck of the draw.