Hmm ... I just tried re-downloading the Bustaball demo from the Wiki. For some reason the ball starts out traveling at angle 0 instead of 270. So basically the ball just bounces back and forth from left to right and you can never touch it. Does this happen for other people? I know I've played it before and it used to work.
Okay, I just found the file that I downloaded the first time and it does the same thing. The ball just bounces back and forth.