In one of my previous post i said
"I have defined SOUND* testwav = "mouseover.wav"; and call a function with snd_play(testwav,100,0); in it".
Later when I changed both the testwav names to mouseover it started working. The strange thing was that the SOUND* testwav = "mouseover.wav"; line caused my panel to not show so I never even got to klick the button that should have played the wav...
But now it works and I'm happy.

Yesterday I tried media_play with a mp3 and got a "mp3 unsuported format" so thougt I couldn't use them with free version. same with an other format. Tried again today after reading your post and it works fine so either the mp3 was bad or I must have screwd it up and used snd_play or something after all.
I do read the manual before I post, I just don't get it all They so need to add more explanations and examples.

This is the problem with sound_vol: "It does not affect the volume of still playing sounds that were started before" and I asumed the same was for midi_vol but that one actually work.
Any ideas on how to make the sfx and voices volume change while playing the sounds? Can't be impossible... Not that important for my project (they only set the volume value for the sounds later on in the game) but it bothers me. I bet others have needed something like this before.
Plan B would be to make the sound stop when slider gets dragged and automaticaly play again when slider stands still / left mouse button released...