My score dropped more than 30 points just two weeks ago and has now recovered those points and then some. The best I can understand is that two auto loans that were refinanced have reported as $0 (caused the score to go from 580 to 620) and then a new credit account was added (another 3 points).
I'm happy that it's back up but frustrated trying to follow the logic. I think I'm just going to ignore the actual score and keep paying my bills on time. When we are ready to do something with our house I'll check again.