Digital photos stored on external drive have gray bars

I won't swear that this will work but I have two suggestions first try to defrag the drive, and second if you can find out more about the camera try to get a software or firmware update if not and the afore mentioned does not work then try this site they offer software and data recovery software. I hope that this is usefull www.softwarepatch.com/tips/howto-file-recovery.html