Not sure if it helps, but with latest CVS you can add in the "remote" section in your MediaPortal.xml the following "undocumented" switch:
2110 is the default port, try to change it to another value to see if that helps. You're not having some firewall or AV software blocking network traffic?
Code:
<entry name="HCWHelperPort">2110</entry>
2110 is the default port, try to change it to another value to see if that helps. You're not having some firewall or AV software blocking network traffic?