I agree with sazz and pkh
the way that it is written, BackupExec keeps the job clock running until all outstanding alerts are responded to
If you have selected Eject-on-End as part of the job description, then for most modern drives, Backup Exec will post an Alert to "Remove the tape and press OK", the job clock will contunue to run
Either remove the Eject-on-End from the job description or set the option to Auto Respond "OK" to this alert