TL 4000 problems with Media

Hi,

We have an issue with our TL4000 with a IBM ULT3580-HH6 drive since yesterday.

It gives on all media the following error message:

The device has reported the following TapeAlert diagnostic information.
Please contact your device manufacturer for more information regarding TapeAlerts.

Critical - The operation has failed because the media cannot be loaded and threaded.
1. Remove the cartridge, inspect it as specified in the product manual, and retry the operation.
2. If the problem persists, call the tape drive supplier help line.
Robotic Library: IBM 5
Drive: IBM 2
Slot: 1

Critical - The operation has failed:
1. Eject the tape or magazine.
2. Reinsert the tape or magazine.
3. Restart the operation.
Robotic Library: IBM 5
Drive: IBM 2
Slot: 1

We have a WIN2008 server with Backup Exec connected to the TL4000.
It recognizes all tapes, its able to read the barcodes (from old and new tapes) but as soon as a job starts it gives the message BAD MEDIA.
When I try to erase a new or old tape its giving the exact same message: BAD MEDIA
An orange light starts blinking on the drive as well. The only way to get the errors away is to remove all tapes from the library.
After that I can add tapes to the I/O slots, import them and they will be recognized. They show up as overwritable/appendable, no orange lights everything green.

Untill a job starts.

There is no warranty or support on the system anymore.

Anyone any ideas?

THanks in advance