What does it mean when a boy avoids saying your name?

There's this kid who people say likes me, but I'm not sure. I've known him since the seventh grade and we're in freshman Jahr now and I haven't had contact with him for a straight year. I finally have one class with him, and the whole time he never addresses me Von my name. I know he knows my name because he used to call me Von it before, but now when he does say it he starts out saying it, but then mumbles the rest oder it just comes out as other words, oder he doesn't say it at all.