Backup Exec 12.5 Changes Media Pool Assignment Automatically

Hi,

I am running Backup Exec 12.5 on a Windows 2008 Server. I use two media pools; "Onsite" and "Offsite". Occasionally during backup jobs, Backup Exec will move a tape from "Onsite" to "Offsite" or vice versa, enabling it to put a backup job on a tape from the wrong pool. Sometimes it seems like this is done because there are only writable tapes in the other media pool, but this is not always the case.

Regardless of why it is moving tapes from one pool to another, I would like Backup Exec to pause or error out rather than re-assign tapes to the other media pool. How do I make it do this?

Thanks for any help!