Setup: SBS 2003 with QNAP NAS unit with user acces configured.

Error: SBS 2003 backup via console fails with error:

“The operation was not performed because the specified media cannot be found.”

However same backup job can be manually run from within NTBackup.

Configure permissions on NAS to allow read/write permissions for SBS Backup User.

http://social.technet.microsoft.com/Forums/en-US/smallbusinessserver/thread/0f506241-6a5d-4b2d-86bd-a4df94b43534