FWIW: I just want to share a compatibility issue I ran into concerning the D2x and the Sandisk Extreme III 8GB card (30 MB/s). (I have other Sandisk 8GB cards, which function fine) When I started using this card in my D2x, I ran into difficulty right away. It would start off OK, but after a few shots it would hang up the camera. The green write light would stay on for the longest time with nothing else going. After that I would get a "CHA" error message on the top LCD and when attempting to view previously taken images, the LCD would show: "this card cannot be used". Turning off the camera and waiting a short while would bring it all back to life again. (The last image shot would display as the above error message, the rest would be fine). When resuming shooting, the same scenario would play again after a few shots. Totally useless card . On Sandisk's website there is no mention of this at all (there is mention of an unrelated issue with the D200). Further creative Googling showed that this is an issue that has been discussed at a number of places (I don't recall seeing it mentioned here). This obviously is an issue with the combination of this card and the D2x. Further reading pointed me towards the solution. The thing to do is to run a "Wipe Disk" in Sandisk's RescuePro program, which will solve the malfunction. Good thing that I happen to have RescuePro :smile:. I ran Wipe Disk with the offending card and...problem solved! The card now functions flawlessly as it should. I hope this may be of help to some here.