I don't know if anyone is aware of this or has tried it, but I have ran into a bug. In IE7 (IE7 Browser Mode and IE7 standards Document Mode for those IE9'ers), if you have the HTML property set of the ManagedIframe panel you will get an error on the page, and the panel will take over the entire screen.
This isn't too big of a deal, because you can work around this by simply creating an HTML page to load into the IFRAME w/ whatever text you want in there.
I was just afraid that I would had to scrap the plugin because it wasn't working with IE7 until I figured out what caused the issue. So I figure I would let everyone know here of a slight bug and the workaround so people are more willing to use this if they encounter the same issue I did.
PROBLEM: When setting the HTML on the ManagedIframe panel, the HTML will take over the entire screen. This only happens in the IE7 and possibly IE8 browser. This is not a problem with Firefox, Chrome, or IE9.
SOLUTION: Use your own HTML page and load the IFRAME with your HTML page instead of specifying HTML to the ManagedIframe panel.
I probably should not have set HTML in the first place, but it threw me off when it worked with FF, Chrome and IE9.
I hope this can help someone out so they do not spend too much time here trying to figure out what is going on for this situation.
Also, I love the plugin and it works great. It properly sizes and loads. It's easy to plug into Ext. My favorite thing about it is the loading as the page inside loads. :)
Keep up the good work!