It seems that there are different versions of libsdl-mixer1.2. Some apps uses the normal version and other apps/games need the +mp3+ogg version. The problem is I cannot figure out how to have both versions installed. check apt-cache policy libsdl-mixer1.2 for available versions
and then install the needed one with
I'm having similar problems with Tux and Tux 2 as well as Beat2x but didn't found a solution yet. Beat2x has sound when libsdl...+ogg+mp3 is installed but Tux has no sound but does when I install normal libsdl-mixer1.2. I know that someone managed to have both versions installed but I don't how he did it, or where I saw the post.