Yes, we have this problem with all (six) of our 3581 autoloaders, and have
had it since we bought them 18 months ago.

The problem seems to be connected to certain LTO tapes, no matter if it's
IBM, Maxell or HP that made the tape. From a batch of 20 tapes I would say
that 2-4 tapes have this problem - at least.

We have reported this to IBM a couple of times, but it's damn hard
to convince a service technician about the problem when it gets "solved"
by replacing the tape with another one. But we're right now working our
way up in the IBM hierarchy to see if we can get any response to our
problems. From another IBM technician I've heard that there might be a
problem connected to damp on the wheels that moves the tape to/from its
slot, the tape skids so to speak. But I don't know...

For us it's very irregular, the same tape might get stuck during a backup
in the night, but work just fine when you try to audit the tape (for
example).

        /Hans