NDX not recognising my laptop i.e "No Servers"

Hi,

I have just recently purchased an NDX.  I have set it up & successfully connected it to the router & as a result I can pick up internet radio. However, the NDK cannot seem to find my laptop upon which all my music is stored on the hard drive.  The NDX quick start instructions show that I must enable media file sharing via windows media player on my pc.  I have done this & indeed if I go to "My Network places" I can see the NDX enabled.  nevertheless the NDX screen still says NO SERVERS.  The quick start quide also says "Ensure the firewall is configured to allow file sharing".  This I am unsure about.  My PC uses McAfee.  I assume the firewall is blocking the laptop talking to the NDX & if so how can I allow it access? 

Paul.