We had this issue - one way to determine the corrupted tapes is if you have
TSM 5.2 or higher (or is it 5.2.2?) server with TapeAlert turned on.

We would then run checkin libv command with the checklabel=yes parameter.

TSM would then generate a message such as the following when it encountered
the bad tape:

ANR8950W Device x.x.x., volume LTXXXL2 has issued the following Warning
TapeAlert: The tape directory on the tape cartridge just unloaded has been
corrupted.  File search performance will be degraded.  The tape directory
can be rebuilt by reading all the data.

Granted it takes a bit of time to checkin all of your tapes reading the
labels but this was much better than a user doing a restore and encountering
this issue (hours and hours and hours to restore a 10K file!).

Tim Rushforth
City of Winnipeg