title: Facebook login button's 1000px iframe causes scrollbar flickering
body: <p>My webapp uses a</p>
  
  <pre><code>&lt;fb:login-button&gt;
  </code></pre>
  
  <p>which is XFBML (eXtended Facebook Markup Language) and is rendered to:</p>
  
  <pre><code>&lt;fb:login-button login_text="" class=" fb_iframe_widget" fb-xfbml-state="parsed" fb-iframe-plugin-query="app_id=[my app ID]&amp;amp;locale=en_US&amp;amp;login_text=%0A%20%20%20%20%20%20%20%20&amp;amp;sdk=joey&amp;amp;&gt;&lt;span style="vertical-align: top; width: 0px; height: 0px;"&gt;&lt;iframe name="f1987cba84" width="1000px" height="1000px" frameborder="0" allowtransparency="true" scrolling="no" title="fb:login_button Facebook Social Plugin" src="http://www.facebook.com/plugins/login_button.php?app_id=[my app ID]&amp;amp;channel=http%3A%2F%2Fstatic.ak.facebook.com%2Fconnect%2Fxd_arbiter.php%3Fversion%3D27%23cb%3Df15dab5c84%26domain%3Dmyapp.com%26origin%3Dhttp%253A%252F%252Fmyapp.com%252Ff1e9e1d5b8%26relation%3Dparent.parent&amp;amp;locale=en_US&amp;amp;login_text=%0A%20%20%20%20%20%20%20%20&amp;amp;sdk=joey&amp;amp;size=xlarge" style="border: none; visibility: hidden;"&gt;&lt;/iframe&gt;&lt;/span&gt;&lt;/fb:login-button&gt;"
  </code></pre>
  
  <p>For some reason, the button contains a 1000 x 1000 px iframe.  Of course, this doesn't actually display as 1000 x 1000 pixels on the webpage, but it's enough to confuse all browsers into temporarily displaying a scrollbar while the button is rendering, on page load.</p>
  
  <p>Is there any way to stop this scrollbar flickering, aside from the hack of hiding the scrollbar in CSS using <code>overflow:hidden</code> and then setting <code>document.body.style.overflow = 'visible';</code> in Javascript once the button is finished rendering?</p>