When you use Windows Internet Explorer 9 to view a webpage or an ActiveX control that is hosted on a webpage, the webpage or the ActiveX control may stop receiving the focus intermittently. For example, the ActiveX control may seem to be disabled, or the focus on the webpage may be in the address bar after you click the page to try to gain focus.
Note This issue can affect any user interface element on the page that can receive the focus.
This problem occurs because the Tab window is detached from the input queue of the Frame window.
To resolve this issue, install the update that is mentioned in this article.
Security update information
To resolve this issue, install the most recent cumulative security update for Internet Explorer. To do this, visit the following Microsoft website:
By default, the Hang Resistance feature is enabled in Internet Explorer 9. Setting the HangRecovery value to 0 disables this feature; setting the value to 1 enables the feature.
Avoid calling the AttachThreadInput API or other APIs that can potentially result in changing the owner for the Tab window, because those APIs affect the Tab Thread's input queue. An example of an API that can change the Tab Thread's input queue is SetWindowLong.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about the Hang Resistance feature in Internet Explorer 9, visit the following Microsoft website: