The Update server is offline or will not connect.
Has not connected since September 2011
There was a recent discussion around a similar problem - take a look and see if it helps you:
I was able to update from 12.0.0 to 12.0.4 last night without a problem -- so it doesn't sound like the servers are really offline.
There could be some local problem with your setup, or with a locally replicated server (CDN).