Well, there goes a story:
Harmattan has resource policy and suggested control of this policy for games is to include a file which tells MeeGo that the application is a game. That way clicking on vol up/down controls volume instead of switching profiles, but as a drawback it switches off the sound completely when "silent" profile is selected. What is more surprising is that plain application (without the mentioned file) plays music even when "silent" IS selected, but vol buttons switches profiles. I need to control volume buttons manually (not through mentioned file). I already got this functionality (I can reveal I have working quick save/load and fast forward by pressing vol buttons, but this reveal is only a small drop in the sea, do not please me to reveal more). What I got to do is to check how to manually control volume from application, which I suppose is easy. So as you can see, it's not a thing that should be fixed, but rather a feature. I am going to make this as an option.