After updates to the Exchange contacts, client reported not being able to see the updated version. All contacts are shown correctly when accessing webmail but not from within Outlook.
Outlook 2003 was in this instance configured to use the Exchange mailbox in cached mode, the OAB had not replicated to the local machine after 24 hours, so I followed the instructions in the Microsoft KnowledgeBase Article: Administering the offline address book in Outlook 2003 and Outlook 2007
To Force Outlook to update it's OAB (Global Address List)
On the Tools menu, point to Send/Receive, and then click Download Address Book.
- Exit Outlook and then restart it. After Outlook starts, the offline address book download will start one to five minutes later.