In the Microsoft Outlook versions listed in the Applies to section of this article, items in the Inbox appear in duplicate or are visually distorted. This can occur when new email messages arrive or when email items are deleted. If the message is duplicated, the most recent previous message is displayed instead of the new incoming message.
When you click the Inbox folder, minimize the Outlook Explorer window, and then restore it, or when you switch the focus between windows, the immediate visual corruption is corrected. However, the problem may return intermittently, and for different items.
This issue can occur if you are running Windows 7 with a Basic and High Contrast visual theme applied.
To work around this problem, apply an Aero theme in Windows 7. To change the Windows 7 theme, follow these steps:
Right-click in the Windows desktop.
In the Aero Themes section, select a theme.
The duplicate behavior can more easily be seen if the Outlook Explorer window is partly covered by another window when new email messages arrive. Items underneath the foreground window may appear multiple times.
This behavior does not occur in Outlook running under Windows 8.