Thanks for the detailed info, GeoFan. That does indeed look like a bug in that LimeWire is responding with its private IP address even though it is clearly able to accept incoming connections (both sides say 'true'), so downloading from the search results don't work.

As a workaround, if you know how to manually configure your routers for port forwarding, try changing the 'Firewall Config' info to 'Manual Forward' and the port that the router is listening on. In the 'Listening Port' area, make sure that that port is set to the port the router is forwarding to. Generally, it's easiest if both are the same number. For example, LimeWire can be listening on port 6666 -- the router can get requests on port 6666 and forward them to internal IP address at port 6666.

Actually -- it looks like you already set up your routers. However, that might be what's causing it to fail. If UPnP on your router works, LimeWire will set it up itself -- but because there's already a setting on the router, UPnP fails and LimeWire doesn't know what's going on. If you remove the settings from the router, that'll let LimeWire handle everything, and may fix it.