Music Files will not play.

I have Media Share up and running. I am using Windows 7 with WMP 12. I can access my computer and see my music files from the Media Share screen on my DVR - however, none will play (they are not protected files - and there is a music note next to each one - which I understand confirms they should play. All files play with WMP on my computer with no problem. My network between computer and DVR is fine - (I have Direct2PC also and can see my recored videos and play them on my computer). I have enabled media sharing with WMP and as I said, can see all my files and playlists. Just that when I push the select button, nothing happens - nothing plays.I have called tech support and they told me to just check the forum - they had no solution (bummer of an answer on that one!) Anyone have any suggestions?