Outlook 2003, connected to an exchange server, no longer works. I get an error: "The operation failed. An object could not be found," and Outlook seems to use a lot of CPU cycles - sometimes over 90%. I rebuilt the profile as suggested in a MSKB article.
Also, Outlook has been configured to use a form in the Exchange 2005 Organizational Forms Library (using FormsAdmin - see MSKB 241235). When I tell it to no longer use that form, Outlook works fine. However, others in the office use the same form with no problem.