When we upgraded our TSM servers from V6.2.3 to V6.3 all the Linux backup 
clients on V6.3 of TSM --and running 'dsmc sched' all the time instead of 
dsmcad-- missed their next backup.  When that set of clients checked-in to the 
TSM server prior to their backup they received 'ANR0424W session refused - 
invalid password submitted', and the 'dsmc sched' process was stopped. 
Consequently that night's backup was missed.  Afterward, the admins of these 
clients  could run 'dsmc q sched' and get an immediate response, with no Userid 
or Password prompt. After 'dsmc sched' was restarted on these clients, their 
next backups ran normally.

No Windows servers on any version of the TSM client had this problem. No Linux 
clients on other releases than 6.3 had this problem. No Linux clients running 
dsmcad instead of 'dsmc sched' had this problem.

Best wishes,
Keith Arbogast
Indiana University