Job Status remains in Queued state.

I am using BExec 2010 R3 Rev 5204 with a PowerVault 124T tape device connected via SAS. My current issue is that backup jobs job status goes into a "queued" state indefinitely. (No other jobs are running).

Interestingly, catalog jobs instead fail with an error of "Unable to acquire device for the specified pool and media". Sometimes a catalog job will also error with "Error - Mount failed Physical Volume Library Drive not found."

Device Manager shows:

1. "Tape Drive"> IBM Ultrium

2. "Medium Changer Devices"> Dell Powervault 124T Autoloader

Ideas are all appreciated!