Lately I have been having problems with our imaging software Acronis True Image 2010. Often when trying to back up a windows 7 machine it gives me an error similar to "the name or location is invalid please try again" however it has seen and accessed the target ext drive. If I close out and try to use the ext drive on another machine it needs to format. This has happened to 4 separate drives. After some tracking I found the Master File Table (MFT) and its back up are corrupt. Has any one heard of this before? We have used Acronis for years and this has only recently started happening but we are just now in the process of migrating to Win 7. This has worked flawlessly on XP and on 7 many times and I can"t seem to find a reason why this "ramdomly" happens on some backup attempts and not others. Any help would be appreciated.