I use the same router as you (except I use a mac.) I was forced to forward a port for LW. Make sure you do it properly. The most important step is the 1st one, setting up a static ip. If this isn't done correctly then the port forwarding won't work after your external ip address changes.

Steps:
1. Set up a Static ip
2. Forward a port; intructions for steps 1 & 2 here: http://www.portforward.com/routers.htm (see bottom left of page for your model.) I would recommend doing a separate port forwarding for both TCP & UDP.

3. Within LW: Manual port forward instructions & sample image & 2 posts after that.

* Did you configure your firewall so it allows LW full access (advisable not to have 2 active firewalls b/c they can interfere with each other); Firewall configuration instructions (click on link)

You can double-check your port forwarding with this test: Using your browser go here: http://www3.limewire.com:6346/ The page should say 'Your test worked!'. If you can't get to the page then the port forwarding probably needs to be redone.