BP generated fine for me and I cleared security easily at ORD on Sunday. The TSA agent scanned my BP and checked my ID. I did not save the BP to my BB, rather I kept clicking on the link provided in the automated email and it kept regenerating my BP. When I clicked on it after a gate change, the new BP reflected the gate change as well. However, the flight was delayed and as I left the AC at 9pm (after original departure time) and tried to regenerate the BP I kept getting an error. I had to get a printed BP from the agent.