You could try using the Windows firewall & see whether that makes any difference.

I'm not sure about your router issue. See whether this link helps, or have a look on Google to see whether you can find other info.
2Wire 2701HG-G port forwarding problem - dslreports.com

Try changing the port number that you're forwarding. Use 65000 (or something in the range of 49152 - 65535). You'll need to change LW's listening port & port in the 'manual port forward' box to the new port number.
If that doesn't work, try changing the application name to something else - limewire1, LW1 etc (it doesn't really matter what name you use).