Have you tried turning off your Smarthub for about half an hour. When it is turned on it should have been issued with a new IP address which may resolve your problem.
And without me doing anything, the problem has gone away. I can now see those two sites with no problems.
I didn't reboot my router as we'd just been switched to digital voice which means the phone line would have been unavailable. Also my router hadn't reconnected either, it's been connected for over 9 days.