Can no longer see Media Servers

I run PlayOn on my network, and it was working just fine with my WD Live TV last week.  This week I can’t see my PlayOn Media Server.  My PS3 can see the Media Server, my WD Live TV cannot.  I reset my WD Live TV to factory defaults, but that made no difference.  

Any suggestions?

-Brian

I forgot to mention that I can see network shares on the same host without a problem. 

Make sure Playon is Up to Date (they’re making changes about every 2 or 3 days.)