|I had the VDB errors and the Resident Shield not active with 2011.|
The solution that worked on this machine:
Don't bother with the tick/untick Resident Shield save changes game.
Frist, click update now in the AVG user interface if you have the yellow exclamation point on the tray icon.
Then Google search 'AVG 2011 Free Download' and get it from CNet.
Run the software. Click REPAIR and proceed.
Let it go until it is finished.
DO NOT RESTART THE MACHINE.
Give it five minutes or so and check the interface again.
The resident shield will be active.