Outlook.exe has generated errors

Outlook.exe has generated errors and will be closed by Windows.
I have a user that when she is in her Inbox and uses her To: and types a W in “Type name or select from list” within her Contacts she crashes and gets this error. Running Outlook 2000 all patces installed. Tried “Detect & Repair, tried re-install from AdD & Remove Programs. Still getting error. This only happens when using the letter “W”. Anti Virus is up to date and computer has been scanned for viruses. Any suggestions ?