QUOTE(Emily @ June 26 2007, 05:00 PM)

We're new to the mac world and this post makes me nervous. With the PC we always deleted images on the computer and reformatted in camera. I don't have any of the software that came with our cards - totally ditched it

(dumb, I know - but we didn't need it back then.)
So tell me this - with a mac and sandisk cards, how are you supposed to delete the images?
Thanks in advance...
Emily
Formatting the card in the camera will do it.
To the OP: You are 100% sure you formatted the card in that camera before you started your session?
I know I have had issues with forgetting to format a card with the 5D when I had previously formatted it on a different camera ... aka, different formats = no good. So, now, every time I put in a CF card, I always format it even if it is clean - only takes a few seconds and I am sure the card is good to go. (Just giving other ideas on what could cause it. Our CF cards are going strong, but only 8 months old atm. They are aData and PQI mostly.)