title: JavaScript issues in Firefox 9
body: <p>Anyone else seeing odd JavaScript issues in Firefox 9?  We are having two issues.  </p>
  
  <p>The first case is that the instanceof operator is returning false when it should be returning true.  When I inspect using Firebug, the variable is definitely what I expect it to be, but it returns false. However, if I add additional breakpoints within my code, then it'll return true. I can do nothing different except for add more breakpoints and it will start working.</p>
  
  <p>In another instance, we have created a variable scoped within a function which is then accessed globally. Something like this (note we are using YUI 2 to create a global namespace):</p>
  
  <pre><code>YAHOO.namespace("MyNS");
  
  (function() {
    var _panel;
  
    YAHOO.MyNS.showPanel = function() {
      if (!_panel) {
        // code to create _panel
        _panel = new YAHOO.widget.Panel(...);
      }
      _panel.show();
    };
  
    YAHOO.MyNS.hidePanel = function() {
      if (_panel &amp;&amp; _panel !== null &amp;&amp; _panel.cfg.getProperty("visible")) {
        _panel.hide();
      }
    };
  })();
  </code></pre>
  
  <p>On my individual page, YAHOO.MyNS.showPanel() is working fine, but then when I later call YAHOO.MyNS.hidePanel(), it fails because _panel is undefined.  If I place a breakpoint in firebug in both the showPanel() and hidePanel() methods, then _panel is not undefined.</p>
  
  <p>We're stumped.  Because it's a new feature, I have tried turning off the type inference functionality in firefox to see if that made a difference and it didn't.</p>