This is happening on a Windows Vista machine with Office 2007 Ultimate.
I have run repair from the control panel and also the MS Office Diagnostic tool. No problems are reported.
When I started Outlook my mail box opens and I can read my messages. If I click compose or reply then Outlook gives me a dialog that says, "Not Implemented." The rest of office seems to be working fine.
Does anyone know what causes this or the correct way to repair it?