That having to do operations after opening the I/O door and removing the
cartridge does sound a bit familiar. It's just not that often we run
across that. We pretty much have a set daily script that works for us.
When we unload the I/O doors we do shut them empty, and reopen them,
before loading more cartridges. You have to give it some time to run the
scanner across each of our 18 I/O slots. You listen for the clicks.