Boy i like randomly ignores me?

I randomly met this guy at a friend's house. He was really cute and seemed polite and shy, so i figured I would talk to him first. i found him on my friends myspace topfriends so i added him. i messaged him and got his yahoo sn. We talked. At first he was really quiet and didn't talk much. But soon he talked more and actually told me stories of his own. Then he was startin to not be online as much he started to go to bed early for some reason so then i decided to ask him to go out for lunch. We had an okay time it wasnt too exciting, he was quiet like the first time we spoke on yahoo. But then afterwards he hasn't been on yahoo at all it seems. So i text and call him a few times and he doesn't reply everytime. I even asked if theres a problem and all he said was hes been really busy with things. I don't understand. He said he isn't ignoring me that he is just caught up in things but this was outta nowhere. I'm confused why he hasn't made effort to talk to me. Afterall we are friends?