you sure EWF is running, right? well, my first thought was that the flash might have hit its write/erase limit in case EWF maybe wasn't enabled, but you said it's happened twice (on the same card, right?). so what did you have to do to get it working again? also, the ExtremeIII will appear as removable since SanDisk doesn't have a utility to make it "fixed". have you run chkdsk on it?