I'm wondering if anyone else has had this problem. I save an image to an external hard drive. Then I save incremental images to the save hard drive. Eventually, they corrupt. I called Roxco support & they told me NOT to defrag an external drive, unless the manufacturer specifically says to. Using Perfect Disk, the drive shows as not being fragmented. Using Windows deframenter, it shows 90% file fragmentation. If I defrag with Perfect Disk, the images stay corrupt & good ones become corrupt. If I defrag with Windows defragmenter, it sometimes "cures" the corruption. Anyone have any ideas? I don't know whether to be disappointed in True Image, Perfect Disk, or my external drives.