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If removing Tape library from BE server fixes the issue with backups to B2D folder then the issue is definitely with tape library hardware.

http://www.symantec.com/docs/TECH129510

Refer to the last few steps (also copied below) in the following document:

http://www.symantec.com/docs/TECH55748 

1. Check if is there any tape stuck in the Tape Drive of Tape library. If there is any tape stuck then unload that tape using web-based console or Front panel of the tape library.

2. If there is no tape stuck in the Tape drive of the Tape Library, This issue will come up when the tape hardware is at fault.

3. Disconnect the tape hardware (drive/library) from the server and reboot the server. Backup to disk jobs will run fine after disconnecting the tape hardware.

Resolve the underlying hardware issue to fix the problem with backup to tape.

I have seen in most cases the issue is with a tape stuck in the drive. If that doesn't help then invovle your hardware vendor.

Addition Information:

This issue comes up when Backup Exec Device and Media database is not able to discover all the devices connected to the server and thus it pauses all the jobs. In your case it is the tape library and when it is disconnected from the server the jobs targeted to other devices (like B2D) works fine.