Success!
Sound system works.
However, after implementing sounds to the midlet the "MIDletPascal" application itself crash sometimes when I press 'build' right after 'save'. But it's nothing. I just have to turn on the application again, and at second time 'build' button works. Pretty odd however.
Thanks.
So all it's left for now it's highscore storage. First I'll try to figure it out by myself..