She sounded like a flake to begin with. Sleeping with you after only two dates? I'd cut my losses and see her for what she saw you as: A quick romp in the hay.
Sorry if this sounds harsh. I've read your posts for a long time, and you seem like a nice, genuine guy who deserves to be with a nice lady. You guys met at a party, enjoyed a movie together and you made her a dinner at your place. How much could she really have gotten to know you and establish a non-physical connection? Add to that the fact she doesn't want much to do with you after the physical intimacy -- well, I guess I'll just say she was after one thing and, for whatever reason, it didn't blow her mind.
There's a word that comes to mind for women like this, and it isn't flake.