Getting technical help can often be an issue, and Cheyenne has become infamous in the computer industry for clogged support lines. The best backup systems in the world include some form of testing the tapes to make sure that the data is actually written to the tape correctly. One simple aid is to use an option on most backup software that verifies data written to tape. At one of my former employers, we used the verify option but didn't really pay careful enough attention to what we were backing up. Only when we tried to do a restore from this particular void was the bug discovered.
Tape drives are delicate machines and develop dirt over time.
Follow the manufacturer's recommendations for cleaning your tape drive. This is very important. Once the backup tapes are created, you also need to figure how they will be stored. Off-site storage must be a part of any organization's disaster recovery plan. This means that you put in place a plan to move tapes off premises in case of fire or natural disasters, so that you'll still be able to recover your data in the worst of circumstances.