Go to your contol panel and select security center > select windows firewall > select the exeptions tab...
You should get this screen
Attachment 2796

limewire is a exception

I checked your modem paradyne mvl modem model number 6310-a1-200
and it's not listed on the Port Forward site...I was reading the forum there and in a response to someones question they said that if a modem isn't listed on their site it wouldn't have a firewall problem...

Do this Port test
http://www3.limewire.com:6346/

Also who is your Internet Service Provider....