BTW, the last time I flew was in 2009 and when I checked in at the desk and picked up my boarding pass, I showed the agent my drivers license. She asked me if I had another ID with a photo on it and I pulled out my Dependent Military ID card and showed her that. She said this works.
Maybe it has a lot to do with where you’re flying out of. I live in the DC area, and I’ve noticed the TSA screening is tougher there and in places like Boston than in smaller airports I’ve visited (such as Charleston, SC).