After MS System Center Data Protection Manager 2007 install and uninstall I have a problem with ntbackup which reports "The backup device is not responding. Please chech to make shure the device is on, the cables are connected". I have checked the tape device (Tandberg TS800 Ultrium 3) which is working OK (all tests passed), the media (tried with new tape), Removable Storage service is running, there are no warrnings or errors in event log. I found strange events in Control Panel > Computer Management > Storage > Removable Storage > Work Queue: Mount (Completed), Dismount (Completed) and another Dismount (five seconds after first Dismount event) with status Failed and description: "The group or resource is not in the correct state to perform the requested operation.".