Actually, both moving methods worked! I didn't know about the middle-click, but I did know about the right-click - I just forgot to try it. I was so focused on it being something in the configuration. I guess I thought there would have been a way to fix it all at once. But instead, I just moved everything back into place, one by one.
I'd like to know why it happened though, but I guess it's just 'one of those bugs'.
Thanks for the help.