I saw nothing that looked like thread when checking the cutter area. The bobbin case seems fine and clicked back in normally. I stuck the vacuum cleaner hose (with the attachment for small areas) down there as best as I could and hopefully if there was a bit of thread, it's gone. I'm guessing that going around with the little dust brush I could have put thread or dust into the cutter rather than remove it. I haven't been using metallic thread and switched to Aurifil 50 wt after the last cleaning. If anything that should have made it easier for the cutter. If the problem persists, I'll have to visit my wonderful dealer. I think the machine might be overdue for a checkup anyway.
Thank you again.
Dodging the vacuum cleaner hose, Jim says:
If there is thread caught in the cutter you won't be able to get it out with a vacuum. The cutter is made up of two blades, one sliding over the other. If thread gets caught in there it's well and truly caught. If your machine is due for service that should include inspecting and cleaning the cutter. Be sure to mention it to your dealer. If they don't remove the free arm cover they won't see the cutter or clean it.