Hi Guys, Merry Christmas! Need some help here. Just recieved a Sigma APO 2x Teleconverter for Christmas. I have a Nikon D5000 and a Sigma 180mm APO Macro lens. I attached the converter to the lens then the lens to the camera body. All I got was a message saying "Lock the aperture ring to the lowest setting" which I've done but I still get the same message? I've put it on and off several times and still can't get it to work. Anybody got any ideas? HELP!! Christmas and I want to play but my toy won't work! Cheers guys.