George - You seem to be having an untoward number of I/O errors on your
         tapes.  I would first check to see that your 3575 has a viable
cleaning tape and that 3575 Automatic Cleaning is enabled.
A dirty environment aggravates the situation.  If janitorial staff is
vacuuming the area, make sure it is with a HEPA style machine, to keep
exhaust dust from filling the air.
Review the situation with your IBM CE: My CE advocates periodic wet
cleaning of the drive interior and heads, which we have seen make a
dramatic difference when dry cleaning made none.

   Richard Sims, BU