chauchs (7/9/2010)
The initial problem is that the backup takes 18 minutes while the restore takes 50 minutes.Why so much difference?
Is the backed up database replicated? If so, and you don't specify KEEP_REPLICATION in the RESTORE statement then SQL Server will drop all objects related to replication after the initial RESTORE is completed. This can take a while depending on the number of replicated tables.
You can check the progress of the restore by querying column percent_complete in sys.dm_exec_requests for the session_id performing the restore. Does is use 50 minutes to reach 100%?