Problem in HP MSL5000

[pgehlot]

Hello
We have one HP Proliant DL380G3 Server installed with Windows 2003 SP1. we are using this as a Centralize Backup Server with Veritas Netbackup 5.0. We have installed 2 no of Tape Library on this, one is with External SCSI Interface and one is with Fiber Interface. Fiber Interface is connected with HBA Installed in Server. Both Library are having same Type of Tape Drive SDLT320 Installed.

Now we are facing very Vired problem, While Performing Scheduled backup we found that all the Backup Successfully performed with SCSI Tape Library but failed with Fiber Tape Library. We are getting following error message in Event viewer.

Event Type: Error
Event Source: PlugPlayManager
Event Category: None
Event ID: 12
Date: 1/15/2006
Time: 10:21:43 PM
User: N/A
Computer: GVABKP01
Description:
The device 'hp StorageWorks SDLT320 (160/320 GB) Drive' (SCSI\Sequential&Ven_COMPAQ&Prod_SDLT320&Rev_5555\4&5f7407b&0&122) disappeared from the system without first being prepared for removal.

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.
Data:
0000: 00 00 00 00 ....

Is Any body is aware sich issue? Please help us.
Thanks in advance

Regards
Pgehlot