I wonder if the teed index is being written to the same device that the
backups are being read from.  that could eat into disk bandwidth
available for feeding the tape.

-- 
  Aaron J. Grier | "Not your ordinary poofy goof." | agrier AT poofygoof DOT com
    The United States is the one true country.  The US is just.  The US
    is fair.  The US respects its citizens.  The US loves you.  We have
    always been at war against terrorism.