Q. On a recent flight back to the U.S. from Australia, I connected via Beijing. At the connecting gate, passengers were directed through a secondary security screening before being allowed into the gate area. The screeners took issue with a bottle of water I had purchased at the airport and refused to let me bring it on the plane, even though it was obvious I had purchased this water during my connection in the area beyond the initial security check. What's the big deal?

A. We've seen this happen before at secondary screenings in international airports. Bagged and sealed bottles purchased at Duty Free are allowed to pass while bottles of water purchased at the post-security newspaper shop are confiscated. Even more frustrating, there doesn't seem to be a whole lot of consistency around who allows what and when. It's a gamble and there's not much you can really do aside from politely surrender your water and board your flight.