I agree with the previous poster who said she's either shy or doesn't want to go out with you. I know you don't want to hear that, as it hurts our feelings--even if we are guys. But, nebsmudge, believe me--there is some wonderful woman out there worthy of your attention.
Inspiring story: Back in my college days, I had a buddy who wanted a date with "a woman" who attracted him. He asked five ladies out, and they turned him down cold. Well, on the sixth "invite", an attractive brunette accepted. Two years later, she became his wife!
You never know what's around the corner for you! Never, ever give up!
PS: My friend and his bride are still married today!