It's Holiday Cinemas right next to the Motel 6, right off Baltimore Pike. I do not go down to Frederick often but downtown is really nice. I wish there were budget theatres in Montgomery County, paying $10+ for a movie is just stupid, and when they say the movie starts at 3, it starts at 3, since they don't play too many ads.
Ah, right. I used to always go to movies there with my parents when I was a kid.