What about "Gleaming the Cube"? I haven't seen it in years so I bet it really sucks, but at the time...! I remember all my skater friends getting soooo excited cuz Tony Hawk did all the skating in it (keep in mind, that was before he was a household name).
I remember this movie about a kid who had a skateboard that was magic, or alive or something like that. I guess that's not what you mean by skateboard movie but it just shot to mind when I read the title of the topic