Hi Ellen,
Have you confirmed that Outlook is working in 'Online' mode (Send/Receive>Preferences)?
Have you confirmed that Outlook is configured correctly? See:
http://support.microsoft.com/kb/2659085.
For a discussion, see also:
http://social.technet.microsoft.com/...e-2cd0e626d9cb
Have you tried repairing the Office installation (via Programs & Features > Microsoft Office > Change in the Windows Control Panel)?