HP MSL5000 tape library goes offline when inactive

[Tomex07]

Hello,

My client has a HP MSL5000 library with Data Protector 6.11. Backup works fine...when the library is online. After about 1 hour of inactivity the library goes offline. I have to manualy touch once the front-pannel and then reboot the server before the tape-library and the Ultrium-tape drive are visible to W2K2003 R2 SP2.
I have:
- upgraded the firmware of both the librairy and the tape-drive
- updated the storpro miniport for Windows 2003 (KB943295)
- checked the two parameters on the control pannel of the library :
              - Library Remains Offline After Power-up Initialization
              - Auto Power-Up An Installed Drive After Timeout

If you have any ideas, it would be great!
Thanks.