I had the same problem, but I was able to fix it and I have music now.
The way I see it. It could either be a problem with your .cfg edit or with the folder where your .acm music files are located.
Did you edit your .cfg to look like this?
music_path1=DATA\SOUND\MUSIC\
music_path2=DATA\SOUND\MUSIC\
And are your music files located at C:\Program Files\Interplay\Fallout 2\DATA\SOUND\MUSIC
Because for some reason, the newer releases of Fallout 2 come with another music folder located at C:\Program Files\Interplay\Fallout 2\sound\music. Which is where the unedited .cfg looks for music (music_path1=sound\music\) even though there are no music files there. You may have edited your .cfg, but put your music files in this other folder by mistake.
Actually it doesn't matter which music folder you put your files into, as long as the music_paths in your .cfg is correspond to that exact folder. The music should play then.
Hope this helps.