I recently updated the free version to 10.3.225 and since then I have been unable to access the address book in Outlook 2003. I am running Windows 7 Home premium. I did the same update on my wife’s laptop - she also runs Outlook 2003 and Windows 7 professional - and the same thing has happened. I have uninstalled Avast and am able to access the address book after the uninstall. However, after a clean reinstall of Avast the address book is again unaccessible.
see recent posts about going back to version 2218