Yup, I had yet another escape today. Ros was gone this evening when I was doing poopy-paper checks. Luckily, she is a believer in the Ten Foot Rule, and I found her under some clothes in the bottom of the closet right next to the rack. She was pretty cold, but otherwise none the worse for wear.
If I would leave my rack system alone for more than a month, I could probably get it set to where no one could get out!