title: Firefox bug with arrow keys jquery
body: <p>I have issues with Firefox and keydown function.
  It will not trigger the function in Firefox but it works in Safari and Chrome. I know preventDefault is the cause of the problem, but I want to block the default scrolling and trigger an other function.</p>
  
  <pre><code>$(document).keydown(function(e){
      if(e.keyCode == 40)
      {
          movePointer();
          e.preventDefault();
      }
  });
  </code></pre>
  
  <p>Does someone have other sugestions?</p>