I wasn't going to post anything more about this, but since the thread has opened up again, here goes.

I didn't have anything to do and it was raining like mad, so I reset the remote and relearned everything.

After I got done, I found another key had locked up on a different screen, so I am back where I started. Maybe someday I won't have anything to do and it will be raining and I can reset it again.

Both commands that locked up my 3100 were from my Sony TV remote RM-Y182, and I have never had a key lock up from any other remote.