Humboldt,
Your modem doesn't seem to have a firewall...did you try reconfiguring Norton?
A lot of Cox customers had trouble using LW, not too sure about SuddenLink.
There are a couple of points in their AUP which could suggest that they're anti-p2p but I can't find anything to say that they're definitely going to cause problems.
http://www.suddenlink.com/About-Sudd...nd-Policy.html

You could try connecting through a different port , say 64049...tools > options > advanced > firewall config & you can change LW's listening port.