Back-up to external HDD's works fine, and verifies (using ATI-11, final build, and Vista SP 2). However, latest backup to internal secondary HDD would not verify (either when did an incremental and tried to verify, or when later tried full back up and tried to verify). Back up that would not verify otherwise seemed OK (would mount up and I could explore it - and seemed the right size). In past weeks and months, back up and verification to this secondary internal drive went off without a hitch. Have read recent previous threads on verification - so tried to verify after boot up from ATI rescue disk, in linux environment - and the full back up that would not verify in windows verfied with no problem. I would imagine the opposite is more common - that back ups within windows environment might seem OK but bomb out when boot up with rescue disk in Linux environment. Is this indiciative of a problem just in secondary hard disk (or its cable) rather then a memory problem? If so, why did it work in Linux? Maybe the key to the mystery is just the re-booting of the computer between the verification attempt within windows and the successful verification within Linux? Any thoughts would be appreciated. Have NOT yet run memory diagnostic, or run chkdsk on the secondary internal drive, or attempted to restore from this latest back up.