Aw, that sounds really frustrating! :-(
My advice to you is to ignore the girl if you want to hook up with her. It's true of both sexes, but girls definitely love attention, and sometimes they're shameless about extorting it out of their male friends.
I went through a situation recently where I was hooking up, lightly, with a girl for years, only to have her recently, after I became single, say that she only wanted to be friends with me. She knows, absolutely, that I would continue to hit on her and flirt with her, so I gave her an ultimatum. It was either hang out with me and we can date, or we'll go our separate ways.
She chose the latter, but I don't regret giving her the ultimatum. It made me feel pathetic to be the cat pawing at the dangling string. Fuck that.
Anyway, hopefully my little anecdote provided a helpful glimpse, if not entertainment. Hang in there and try to focus on what you want to do with your life and what your interests are. I've been doing that so intently lately and it's only led to great things.
Edit: And because the universe has a GREAT sense of humor, guess who just logged on to AOL Instant Messenger?