Browser catch out focus when user try to use Tab navigation in your application.
A little recipe in order to overcome the loss of focus in IE when navigating within the Flex application using the Tab button. All you need do is set the parameter.
All you need do is set the parameter
<param name="SeamlessTabbing" value="false"/>.
That are native to the tabulation in order to remove the closure of a Flex application that the user has not used the tab button only within an application, but could move in the browser address bar, etc. All you need do is set the parameter.