I am so glad I read this post! It reminded me to check my credit card activity to make sure I wasn't charged Sunday night for a room I left at the Hilton O'Hare. They had given me the room behind the elevator and I just couldn't sleep so I left and took the shuttle to the Doubletree which is where I should have gone in the first place since I had a distressed rate from the airlines! (I don't think clearly when I am cold and tired)
Anyway, sure enough, they had charged me at the Hilton. Luckily, I was able to get a credit for the charge. Perhaps, because they checked the Doubletree and found I had indeed stayed there.