About three weeks ago we changed the back up tape set from one tape to two since our data was getting heavier and we needed more tape. It started to work fine. We set it up so that Mondays it would use Tape 1 & 2, Tuesdays - Tape 3 & 4 and so on. But itermittently, it would interchange the tape selection. For instance, on Tuesday instead of using Tape 3 & 4 it would use Tape 4 first and then Tape 3. But the following Tuesday it would work fine again. Once it even used the same tape again for it's next set. On Thursday it was supposed to use Tapes 7 & 8 but it used Tape 8 for the first media set and then tape 8 again for the second media set and obviously the back up failed as it tried to overwrite the back up catalogue. The media descriptions have been set correctly. Pls help