Mark is absolutely correct.  This is an issue we have as well.  To solve the
problem we are running post processing of the output looking for a bogus
situation and setting return codes.  We use an external scheduler, so we can
do this.  With the TSM Scheduler you are just screwed if you are not
satisfied that a successful session does not necessarily equal a successful
backup.

The worst problem we have is the TDP for Exchange can get a 425 return code
because Norton Anti-virus has the Exchange store tied up and you still get a
successful backup.  This takes a bounce of the Exchange Server.  The issue
is you can go weeks without realizing you have not gotten an Information
Store backup.

Typically, I use SQL to looke for the message id and failed and that is how
this one is found.