Hi Ottoga, thanks for the suggestion. I did as you suggested, but it didn't work. the 7D still says 'Change Card' I had tried to format to MS-DOS with the OS X Disk Utility, but when you mentioned NTFS, I thought maybe I needed to get a different app to do that. I downloaded a trial of "NTFS for Mac OS X" and formatted the card to NTFS. Same result. I do appreciate the help Merry Christmas