Backup Dilemma - Ideas?

HI All,

We've been using DisXtender 6.10.040 on our Windows 2003 SP1 file server since August with a centerra on the backend as media.

Initially we'd setup the rules and retention on the media to 0 days so that users could still delete and/or modify the files that had been archived. It worked great, until a user had files that "mysteriously" disappeared and asked that their entire home directory be restored from tape. At this point in time we'd been backing up using the fast method, only taking the stub info, with netbackup 6.0 MP3. As such, when the user deleted the stubfile, it sent a command to centerra to also delete the blob. So, when the stubs was/were restored and the user tried to access, it caused errors on the media that the stub pointed to for its blob. This caused the transaction logs for that media to freeze on the invalid transaction and made xtended files inaccessible for all users who had data on that media, until I (with the help of support) stopped the DX services, opened the transaction log in the transaction log viewer and set the questionable entrie's value to "completed" rather than pending so that DX would not try to process that log entry again. Once services were restarted, all was well, so long as nobody ever tried to access a stub whose blob had been removed.

So, after those events, I changed the backup type to long - so that Xtender will read the data from the Centerra during backup of the file server... since then, our backups run ridiculously slow and do not complete within our window. I've already stopped our active scan on the file server from scanning on reads, so it should not be impacting the backups.

In efforts to allow us to change our backup back to the 'fast' option to get our backup speeds back, I've been experimenting on setting retention on files on a different extended drive and was wondering if anybody knew what has to be done to allow a delete after the retention time has expired... currently, for testing, I set retention to 1 day, then tried deleting a file 2 days later, and I still get a denial from DX. Is this a default behavior of the centerra when used with DX? Or am I missing a setting?

I've also noticed a setting under the options tab on the extended drive properties that says "prevent delete"... I tried that one out, without retention set, and it didn't seem to stop me from deleting anything. Is there something I'm missing about the way this setting works?

All in all, as I see it, the only way for us to alleviate this backup time issue is to do one of the following:
-find some way, or setting I can change to help speed this along.
OR
-set retention on the files so that they cannot be deleted
OR
-I'm sure there will plenty of great suggestions that I may not have thought of yet.

Any input is greatly appreciated. Thanks.