I'm scheduled to fly IAD-ORD-CLE tomorrow morning, but I want to stand by for DCA-ORD-CLE (plenty of seats on the DCA-ORD flights, so I don't think it will be a problem). However, I do want to check in online now or later today to be able to hand the DCA folks my printed BP and ask to stand by.

Of course, Mr. Chicken online, no matter what browser or login method I use, just dumps me at a blank screen. Seems people were talking about this same problem 3-4 days ago ... way to go United.com!