Outlook has combined 2 email accounts

Hello,

I set up my Outlook Mail to receive mail into my email address and my wife's email address and display each of our incoming mail separately. One day, a couple of weeks ago, the inbox just shows my email address, eliminated hers from the display, and shows both her and my mail under my email address. I have checked everything I can think of. The account is still set up for 2 addresses, the view is set to sort by email. I can't see anything that has changed other than that the emails are no longer sorted to her and to me separately. Any suggestions out there? I have a Toshiba laptop running Vista.