Since a couple of days I have constantly this message.
For some reason the wifi reception is four on five but the browser gives me the above message.

If I connect to other sites it's the same. Newsfeed doesn't work either.
When I restart I am sometimes lucky.
It is random.

Small gues that I have : their is something wrong with our IP server (the fileserver distributes the IP numbers. Mac OSX)

Any people have the same?

I have noticed same (tried also fixed ip-addresses). I began to start connection via Connection Manager->Connect (not simply starting a browser and using default connection), and the odds got better. Maybe it is just voodoo, but you could try.