Why do I get the error '/dev/st0: Cannot read: Input/output error' with a tape drive while using the tar command in Red Hat Enterprise Linuxe AS 2.1?

Release Found: Red Hat Enterprise Linux AS 2.1

Symptom:

I need to read data from a tape drive that is write protected, but every command gives me errors. For example (cpio, tar, etc.) give the following error messages:

tar (child): /dev/st0: Cannot read: Input/output error
tar (child): At beginning of tape, quitting now
tar (child)...