Guest0007: You probably do need port 6346 to be opened on your modem. So far as your modem/router goes it's difficult to say b/c I don't have a model no. However, if you look at the bottom of this page you'll be able to see several models & one might be or fit yours as far as instructions go. 1st you'll need to set up a static ip for it to work properly. http://www.portforward.com/routers.htm

Other instructions may help: Setting up a static ip for Linksys & for port forwarding THIS might help

If you're using LW 4.2 or earlier then refer to this: Force IP instructions & sample image or otherwise if you have LW 4.4 you can try leaving it up to LW to try to configure the best firewall setting. Else try the 2nd option & use port 6346.

I presume you configured both your firewalls(XP & Zonealarm) for LW's access: http://www.limewire.com/english/content/firewalls.shtml