can't hear downloading song in preview
 

Hi there,
when I'm downloading a song and want to listen to it, I press the preview icon and it shows up as playing in the little blue box of lower right corner, but I get no sound. It also does this even after downloading is complete and I try and listen to it in the library. I have tried downloading the same song, different sharer/file, whatever thats called, and it does the same thing. There are four stars beside the song quality info so why can't i get a preview to listen to? Any ideas? Thank ya much!