first double check all the format settings are correct as well as username/password/port;
also check the Centova panel to confirm your server is started and can accept the source [having access to more than one PC or a multi display computer helps, as well as friends who can check the other stuff (they can be in different locations to where you are, as long as they can contact you (an analogue telephone is still useful at least for this; as it will work even if the broadband doesn't; mobiles can make noise/interference on some audio equipment if brought too near)