Following these steps (w/buttons) will demonstrate the problem. This sequence simulates how we initialize our application.
You will note that the buttons in the panel's .swf, which are over the yahoo iframe, are unresponsive. Also, if today's yahoo logo has an animation, it may "bleed" through to the panel as well.
Please note that we must create the panel first as the .swf provides means for other elements on the UI to initialize/instantiate. We keep the panel with the .swf alive and hidden by setting it off screen (-1000, 2000). We cannot actually hide it as in IE hiding the div with the .swf causes all external interfaces (means of talking to the .swf) to be lost.
The content of our tabs is dynamic, depending on what else is selected on the screen. We must use iframes as we are repurpusing some 'legacy' code. The iframes are created dynamically each time. We were unable to just create an iframe for each tab and set its 'src' because that messes up the browser's history.
Finally, this issue is totally dependent on the order in which things are created. Creating layout and tabs w/content AND THEN creating the panel does not exhibit this problem (doing step #2 then step #1), however, as I've stated we must create the panel first as other items depend on it.