If you’ve installed Office 2010 Service Pack 1 (SP1) and are experiencing either of the following issues with Outlook 2010 SP1:
You should install the Outlook 2010 hotfix package. It’s part of the Office 2010 Cumulative Update (CU) for August 2011.
For more information about the latest Office products updates, see the Update Center for Microsoft Office, Office Servers, and Related Products.