...
>   volume state.........Volume present in Library, but Inaccessible
...

The volume may or may not actually be in the library.  When a tape
gets stuck in a drive, it may remain there - and there may be no
Int Req or other obvious indication of the problem.  If the operator
responds to such a problem, he may remove the tape from the library
and leave it on a desk somewhere, as though a tape fairy was going
to come along and do something with it, rather than the operator
putting the tape into lib cell 1 for automatic putaway.  (I went
through this.)  The library remains dumbfounded as to where the
tape is.  The operator remains dumb.

Use mtlib to query your drives and see if there the tape is stuck
in one of them.  Your server Activity Log is what you should be
looking at to see where the tape was last seen by TSM.  You can
also try TSM SHow LIBRary to possibly uncover its whereabouts.
You have to hunt, then gather.

    Richard Sims    http://people.bu.edu/rbs