Not sure if this will work. I've just tried it on my machine and it seems to have worked ok.
go to start -> run -> type regedit and hit enter.
browse to... HKLM\Software\Microsoft\Windows\CurrentVersion\policies and select the "ratings" directory. In the right hand pane, there should be for registry entries, the last of which is called "key"
Under the .Default entrie, there should be one called FileName0 or similar. click on file -> export (just to be on the safe side) and save the selected branch of the registry to the desktop or somewhere. Rightclick FileName0 and delete it.
Open Internet explorer to be greeted by a "check for missing information in content advisor" message. ok it, and you'll get the content advisor popping up to get a password from you. click ok without a passwrd and you get a "wrong password" message. Ok it, and close the IE window. Maybe this will happen a few times. On mine, the next time I opened the window, I had full internet access and Content Advisor was once more disabled.
Hope this helps.
EDIT:Thinking about it, would somebody techy like to test this? it almost seems too easy. Obviously enable content advisor first, then backup the appropriate part of the registry and just retore it if it doesn't work.