For quite a few weeks now, Zoe has not had a single accident in her crate. Starting Friday night, however, she's had quite a few accidents in the crate. I do not keep her in there for extended periods of time. During the day she's barely ever in there unless I leave the house. The only time she's in there for a while is at night when I'm sleeping, but even then, she was doing well with keeping it dry. Why all of a sudden is she having an accident everytime I put her in there? I never punish her for accidents, I praise her when she goes potty outside....what's going on here??