I need help!

suddenly, and i dont know why, limewire just stopped connecting, in fact all P2P programs stopped connecting. Winmx works, but i like limewire. So i ran "netstat -a" found the port that my cable modem is running off of and set the listening port to that. it connected for a little while and then disconnected. I ran "netstat -a" again and found the port keeps on changing. I don't know why this is happening. is there anyway to keep this port from changing so that my P2P works.
by the way, i have full internet access, but just no P2P connection and im running off of a wireless internet through a router.
THANKS GOES OUT TO ALL THOSE WHO RESPOND!!!