I found those tests can be a little deceiving at times. For example, UPnP routers will close ports for receiving unless a particular program with UPnP abilities requests the router to open the port whilst the program is open. So ... if I had LW port set to a particular port, then it may actually show as being open by the test. For some confusing reason I found this to be true with port forwarded devices also.

* Edit: What i meant was I needed to have LW open with the port setting to the particular port for the test to work. If LW was not open, then the test would say the port was closed. And this seemed to apply to both UPnP and router manually port forwarded to the specific port. Perhaps this was just a particular router or mac issue. I don't know.