Relationship Advice

For the longer, more specific and event driven question, see the link in additional details.
I’ve known a girl for a month (I had taken her to my prom). Two weeks ago we spent some time together, at her sister’s grad party and at a store. She had shown some signs of liking me such as saying “I’m so glad I’ll get to see you through the whole summer,” touching me in friendly places but frequently, pressing against me while we sat next to each other, and when it seemed like we were headed for her house, telling me that I can see her room. This wasn’t the only time she acted like she liked me, it was just that this time was more obvious. At school two of her friends told me on separate occasions that she likes me. We had a date set for last week to go to the movies, where I was going to tell her I like her.
It turned out (over myspace) she had to go out of town for the whole summer, and she apologized. She had gotten a boyfriend the day I found that out. I didn’t mind because it’s not like she’s here and we had no prior commitment, especially since I haven’t told her how I feel, and I know it’s going to fail because all the boys she dates cheat on her or do something else, and I figure if her boy’s really a dog, when she talks to me she’ll appreciate me more. When I sent her the professional prom pic-taken at the prom through a studio-I ordered of ourselves, she temporarily had it as her background layout until her boyfriend told her to change it to a love-themed layout. My plan was to take the opportunity to get to know her more while we were apart so we could establish a stronger friendship when she came back in town.
We talked over myspace until recently she stopped replying to my messages. My sent messages shows that she’s read them and I saw comments from her on two other boys’ pages (not her boyfriend) at the times I’ve sent her a message. We haven’t talked in a week, I have no idea what’s going on, what should I do? I was thinking I should wait one whole week and message her again, and if she doesn’t reply again apologize for whatever it was I did to make her not want to talk to me. If she doesn’t like me anymore, I should have known it was too good to be true. I’m not a thug, I’m not tall, I can’t drive yet, and I actually care about whoever my current interest is, which no girls today want.