Try a bit of this action here
http://blogs.msdn.com/astebner/articles/487537.aspx
and here's another
http://thegreenbutton.com/forums/thread/81418.aspx
it would seem from reading these posts, that it is something to do with port numbers, firewalls, and possible some software blocking certain internet stuff like https:, but only after findling does it somehow work again, even though nothing has changed.
despite that i have turned off firewalls, virus checkers and spyware detectors it doesn't seem to have resolved much for me.
will try it again one more time, maybe i wasn't thorough enough with my investigation
let me know if you have any luck from your side