Outlook Top of Information Store
Actually I got to thinking this might make a good blog post so I took a closer look - Try this:
On the folder above the inbox, right click and select "Data File Properties", select the home page tab and uncheck the "Show Home Page By Default" box and tell me if you see your mail there after you ok out of the dialog.
Butch Adams
The folder above your Inbox labeled with your Office 365 e-mail address in Outlook is the "Top of Information Store". You can see the following article for more information about recovering information which has been accidently moved to the "Top of Information Store" in Outlook. This article was written for Outlook 2003 and 2007 but should work for Outlook 2010 as well:
http://support.microsoft.com/kb/289949