One behavior I see in many people is standing by waiting for what they want to have happen, happen to them.
If you want to get to know a woman, talk to her. If you're interested you won't show it by hiding in a corner peeping out at her constantly (figuratively or literally). What you're doing now may be coming off weird to her. You approach her repeatedly, offer an extraciricular conversation then disappear. What signal is that supposed to send? Chances are she'll dismiss you, if she had any interest, or assume you're playing games with her and turn her off from any future communication.
Either hide silently in the shadows spending your life wishing or get to it and speak up and take some action. But this come here/go away approach you're doing now will definately backfire. And it may backfire beyond this one woman if she chooses to inform other women of what she perceives as you playing games with her.
My thought is approach her with the intention to get to know her as a friend. This takes pressure off of you and allows for a more natural connection to form, if one forms. And if it does then it can be transitioned easily into a romance as all that's required will already be in place.