Open LW & leave it open for at least 20 mins & then do this test:
Bug Report instructions & sample image Is the result True/False? If False then there is probably something blocking LW's full access.
You will need to make exceptions rules within your firewall for LimeWire.
That's odd that your port settings should be different to the default. The default port for LW is port 6346 but it doesn't really matter so long as your LW has free access thru the particular port no.
A possible issue could be your modem if it uses a NAT firewall. Most hi-speed modems use NAT. But some of these have UPnP (Universal plug & play) abilities which means that LW will communicate with the modem & access will be given thru whichever port it's set for. However, if your modem doesn't have UPnP abilities & it does use NAT, you may need to do port forwarding (opening a particular port.)
If you do the above test & find your answer is False, then set your firewall. If still False, then check your modem & post back the brand name & model number of your modem. I'll see if I can find out if it uses UPnP or not or direct you to port forwarding instructions if I can find any for your particular model.
In the meantime, set LW's listening port to 6346 & set it to the UPnP option.