I can't get this to work either. WDTV Live sees four shared folders, i have more than 4 shared folders so i have no idea why it sees these and not the other ones. I have added them all to be shared to "everyone". Very frustrating. I tried to add them via Windows Media as well just for kicks.
I shared downloads folder, can see it, i made a folder DVD, can see it. Made a folder MKV CAN NOT see it. I shared pictures, can NOT see it "unless" i'm going through pictures via media server (shared in windows media), i can not see it via network shares. Just the same stupid random 4 shared folders show up, and MKV is never one of them.
ps im using windows 7