GFD or Tom,
either of you all ever have trouble with your SD card's lock? That little switch thing on the outside of it? I have 2 cards that the "lock" has completely fallen off and now I can't upload any more pics to it nor can I delete pics from it.
ALSO- I have one card that is stubborn. I have about 400+ pics on it, but even with the card unlocked it WILL NOT let me delete pics off of it. It will let me add pics to it, but not take them off.