Can't add more then one tape to a pool

I have a problem with adding more than one tape to a pool after upgrading a system.

I have decided to upgrade the system because of the "No tapes error" (well described in KB article http://kb.open-e.com/How-do-I-correc...error_84.html). I did not managed to resolve this problem with deleting the logical volume, where backup database was located and re-enabling local backup function.
After the upgrade from DDS v.5 build 3216 to probably the latest 3562 version (with a couple of intermediate versions), I can add only one tape from Quantum SuperLoader 3 with Ultrium LTO4 drive. All of the tapes are listed. When I am adding a couple of tapes to the pool, autoloader cycles through them, but only the first one is labeled and added to the pool.

Please help, cause I can't do a backup of the LV's with a capacity above one tape.

P.S.: later I have encountered more-less the same problem with only one difference: tapes were added to the pool, but during a backup when autoloader changed the tape an error "Error 1: Cannot find tape or user has stopped the backup task" appeared.