On Jan 24, 2006, at 10:18 PM, Meadows, Andrew wrote:

...what causes it?...

Phantom data on volumes is a problem that just won't go away in the
server software. Your case may be related to the cause in APAR
IC48152. You might pass it by TSM Support. It would provide valuable
perspective for your pursuit to ascertain the last write datestamp
for that volume: sometimes it is the case that the problem was
instantiated under a prior version/release, and only evidences itself
once the data on the old volume finally expires.

  Richard Sims