Netbackup 6.0 and Storagetek L180

Over the past couple of months I have been working with our support staff in trying to get an issue resolved but so far have not had much luck, so hopefully someone else has had a similar problem and might be able to guide me to the proper solution.

Currently, I have StorageTek L180 tape library that is connected to a Master and Media Server, both are running Netbackup 6.0 MP4. The master server is running Windows 2003 Enterprise Edition SP2  and the Media Server is running Windows 2000 Server. The master and media are both connected to the library via fiber cables.

Each time that I remove a series of tapes over 10, the second and third pass are always falls short with only 9 tapes in the CAP instead of 10. Each time the first mailslot is empty.

Our support has already replaced the head and the controller card on the library with no luck. They have also had us update the device mapping file more than once.

I am beginning to believe that this could be a software or even a driver related issue, if any one has any thoughts on this, please let me know.

Thanks in advance.