I edited some photos directly in iPhoto and after having to force-quit iPhoto, I returned to find the photos corrupted - they would no longer open and would display only as blank photos (with an infinitely spinning "thinking" cursor). When I try to open in Preview I get the message "Couldn't open file - it may be corrupt or a file format that Preview doesn't recognize". These are recent photos that I haven't yet had a chance yet to backup. Any suggestions?? I'd be grateful for any help, thanks!