Are you checking the files with Bitzi?? Bitzi is a site where other Hosts Rate the quality of the files. If you are not using Bitzi, the possibility of the files that you have downloaded are fake is very High.
Check out the threads below for more info & tips, including how to use Bitzi.
Fake files showing up in search results How to find music (tips for video also)
VLC will play just about anything and this is the reason I have a feeling they maybe Fakes.