hey, My LW was working like a week ago and I just now tried to use it again and when I started it up it said "LimeWire was unable to setup a port to listen for connections"

now I can't connect and d/l any files of any sort. What all do I need to do? The only firewall I have is the Norton's personal firewall. And I'm usin WXP. Can anybody tell me what the problem is and how to fix it? thanks!