You must forgive Ramo, he tends to get really really drunk from time to time.
What are you installing the game from, a disc or an image? If it's a disc, it might help to make an image out of it and use that to install and play. If it's an image already, I'd probably try making a new one... but I guess that's kind of a long shot if the files play fine in a media player. Still worth a try, though.