Exabyte tape warning

[Richard Korry]

We just installed an exabyte on a Sun 4/480 running 4.1. We are starting
to get the message:

st2:  warning, the tape may be wearing out or
      the head may need cleaning.
st2:  write retries= 829 (14.3%), file= 2, block= 4771

where the write retries, file and block number vary. Is this a real
problem or an artifact of something else? The tapes are all Sony P6-120MP.
The problem does not happen on the initial writing of the tape. Post or
email any replies. Thanks