BackupExec 2012, use of media sets

Hello,

i (or more precisely a customer) has a "problem" with duplicate to tape jobs.

The jobs are configured as follows:

Month to Disk -> Duplicate to Tape (Media Set Monthly)

Week to Disk -> Duplicate to Tape (Media Set Weekly)

Day to Disk -> Duplicate to Tape (Media Set Daily)

Problem:

If Tape A is used for a Monthly Backup and becomes overwritable again, BE uses this tape for any job. So it becomes a Daily or Weekly Tape.

The customer wants that, Monthly Tapes stay in their media set. According to the customer, this was usually the case, but since 2-3 months BE doesn't behave like this anymore.

Any ideas?

Kind regards,

Dave