frankly? i'm gonna say that i think this bloke is messing with your head. he's into you, he's distant, he's single, he's not...truthfully, i think you should only give someone your time who deserves it and this guy doesn't seem to be taking you seriously. but i also realize that just because i said this isn't going to make you stop fancying him, and you shouldn't if you think he's worth it. i mean, what do i know? i've never met the bloke.
as for his AIM message it could be a number of things, but if you really want to know? i say ask him.