In the past three weeks I have been consistently locked out from using the check in machines at the airport or the online check in on the website. When I use the machines or try to check in through the website, the machine refers me to the agent for "special handling". This has happened to me on Delta, American and yesterday on Continenatal. Oddly, I had no issues flying on Air Canada which I did last week. When I go to the counter, the agents ask for my ID, quickly print out my boarding pass and report no problems with my actual reservation. When I ask them why the machine did not work, they have no idea. Obviously this is very annoying for me as I have to speak to an agent instead of just using the machine. I travel about once a week for work, so this is a real pain.

Has this happened to anyone else? Have I been flagged by Homeland Security?