I'm having an unusual problem with a 500 gig Western Digital Mybook USB Drive (formatted as NTFS). I have two of these drives that I use for copying important files, one at home and one off-site for backup. I periodically bring the off-site volume home and sync it to the home version. The last time I synced the drives, I checked the off-site volume afterward and it matched the home version exactly. The off-site version had 3 new files, and about 100 files deleted from the home drive were also deleted on the off-site copy, and the recycle bin emptied. When I plugged the off-site volume in at my office, however, the sync had gone awry. The 3 new files were there, but the 100 files I deleted had reappeared, intact, and could be accessed. THinking I had done something wrong, I took the drive home and resynced. I made *sure* the files were deleted on the off-site copy. Sure enough, though, when I plug the drive back into my computer at the office, the files reappear. How can this be?!? I deleted the files at work and they're gone now, but does a USB drive have different directories of files based on the computer to which it is attached? I wouldn't think so.

After deleting the files did you empty the recycle bin? Also, there are different settings that you can use to sync. If you wish to have both drives contain ANY file available that can be done but that would also place the deleted files back on the drive they were deteted from. Bottom line is you need to check the settings to see which drive is syncing to which. Might be a setting to NOT remove any files from either.

It's not the sync. At home, the drive shows 420 gigs free after the sync, the same as the main drive. However, when I plug that same drive in at work it shows only 360 gig free and 60 gig of files that have been deleted show up again, but only when the drive is plugged into the work machine.

As I asked, after deleting files are you emptying the recycle bin BEFORE removing the USB drive?

If you're not dismounting the volume using the Safely Remove Hardware icon, I'd say you have your answer.