Dave, when you get this problem try accessing google.com, and if that fails try typing in the following:
Into the address bar at the top of your browser not the search box or anything.
Tell me if any of those work or if you still get the issue when using the numbers as above.
EDIT: Also see if you get the same issue on any other computers/devices and try using Internet Explorer if possible to see if you get the same problem.
Edited by Kaytfoh (Wed 19-Sep-12 18:32:12)