I'm sure this question will make me sound immeasurably stupid but...
How do you play external mp3 and it files with the stand alone game they came with? for example, the .its in Spud's Quest and Special Agent and the .mp3s in Lyle in Cube Sector never play in-game. I can open them separately in just about any media player application, but I want to know how to get them to play at the appropriate times in game.
It's strange that they aren't playing for you - as you can play them separately, your system's definitely capable of reading them (though this is pretty much irrelevant as the games should contain the right sound codecs anyway). At a stretch, it could be because they've been moved about since being installed - you didn't unpack all files to the same directory/discard the folder structure when unzipping them or anything?
The only thing I can really do is ask anyone else if they're having this problem.