OK, I think I misunderstood a couple of things or/and didn’t make myself clear. It happens when I’m writing in English. 
Let me start again:
I have a simple preloader with a %-bar that has to preload a small movie with music. The music doesn’t have to stream really, just play when the AS kicks in, which it did. The sound is “exported for AS” and “exported on first frame”. The problem I have is that the preloader doesn’t show up at the beginning of the movie, while preloading. The screen remains blank for a while until everything is preloaded. That’s not what I want. I want the user to see the preloader bar while waiting for the preloader to preload.
I searched the forum and found some similar problems people were having, with a few differences here and there. Apparently this is a common preloader problem. Anyway, I tried some stuff: I disabled the sound’s “export on first frame”. Without this option, my movie preloads like it has to. I can see the bar and the % and everything. When it hits 100%, the movie begins. There’s a “but” though: the music doesn’t get preloaded anymore.
Once again, the music I have is triggered by ActionScript. I don’t know if that’s the problem or not, but it drives me crazy.
Thank you. 