It appears that my memory cards are corrupting when I connect the card to my Mac (MacBook Pro with Mac OS X 10.6.2 and fully updated McAfee Security). I can retrieve the images using PhotoRec (cracking little free program) but I'd rather not have to do this every time... This has happened with two previously functional CompactFlash cards (SanDisk Ultra II) that have previously been used successfully with a PC and happens when either the camera is directly connected to the computer or if a cardreader is used. Could the problem arise from a PC "configured" card and, if so, can this be rectified? I'm a bit of beginner so any help would be greatly appreciated!