Hi
Listen r u using wifi connection? I have tried many things like uninstalling and reinstalling same new version or even older versions still the skype wouldnt connect. then i noticed in my network connection that there is another connection caught by my wifi maybe of the neighbours and after it has gone then i managed to connect to skype!!!! so try to open ur network connections and see if there is an interference from any other conneciton rather than ur own. the minute this other connection disappeared from my computer i managed to log in. good luck. 
