Another oddity I’ve just come across when developing an IFRAMEd Facebook application; the iframe used to display your pages has the CSS overflow property set to “auto” (I think), which causes a horizontal scrollbar to appear when your page content exceeds the height provided (determined by the window height).

As you can’t use CSS or JavaScript to communicate with the parent frame, to fix it you need to wrap your entire page in a wrapper div and use the overflow-x property to kill the scrollbar:

...Application goes here...