Hi, I am using Transmission on my Macbook with Mountain Lion. The port I have set to 51515, but it says port closed. Both on the router (RT-N66U) as on the modem uPnP is switched on. It used to work when I had a different router in the past, so I don't think the uPnP on the modem is the problem. I am using Merlin's build 188.8.131.52.266.23b. Btw, I know I can have the router as BT client, but that is not what I am looking for. I am perfectly fine doing it via my Macbook.