I found this in my application and it seems to happen in your demo for attachEvent as well. After attaching an event, the event fires on the Normal tab. Switch to HTML tab, the event still fires. Switch back to Normal tab and events are gone....
Do you have any ideas why or how we can trap the tab switch client side. I'm getting ready to notify our tech support that this is a bug with your component that won't be fixed in the current release of our product. Any information or help you can provide would be cool. You can see this in your JavaScript API demo by attaching the keypress event, pressing in normal and switching and pressing in html and then switching back to normal.
Thanks!
-Steve Champion