Outlook help

[SzczerbiakManiac]

I have a solution, but it's draconian. Delete the file that stores all that auto-complete information. I would say edit it, but it's not a text file, so unless you're really good at editing hex, you're SOL as far as that angle goes. The file is called "%USERNAME%.NK2" (those aren't wildcards, that is literally the name of the file) and you'll find it in:
C:\Documents and Settings\YOURUSERNAME\Application Data\Microsoft\Outlook

Close Outlook, delete (or better still, copy it somewhere else, just to be safe) the file, then re-open Outlook.