title: Ext JS: Scroll reset on Tab Change
body: <p>I'm using Ext JS v4.2.1 to draw a Tab panel in Screen and show some content -that can get quite big- in each tab. For that, Iuse something like this:</p>
  
  <pre><code>var createTab = function (tabName, panelName){
                      return {xtype: 'container',
                              title: tabName,
                              autoScroll: true,
                              layout: {
                                  type: 'vbox',
                                  align: 'stretch'
                              },
                              items: [
                                  {
                                      title: panelName,
                                      items: [Ext.create( 'MyLongView' )]
                                  }
                              ]};
              };
  
  var tabPanel = new Ext.tab.Panel({
              renderTo: 'testDiv',
              flex: 1,
              border: false,
              itemId: 'tabPanel',
              items: [createTab('First Tab', 'First Panel'),
                      createTab('Second Tab', 'Second Panel')]
          });
  </code></pre>
  
  <p>When I tried that code <strong>in Internet Explorer, each Tab Change resets the scroll position to the top</strong>, a Bug that doesn't happen nor in Chrome or in Firefox. To reproduce it, follow this steps in an IE Window:</p>
  
  <ol>
  <li>Create a Tab Panel, with to Tabs inside them.</li>
  <li>In the first Tab, scroll down to the bottom.</li>
  <li>Then, select the Second Tab.</li>
  <li>Finally, return to the first tab. You'll see that the scroll that you left in the bottom is now in the top.</li>
  </ol>
  
  <p>The expected behavior is that the scroll stays where you left it. Searching through Sencha forums, I found that they suggest the use of <code>hideMode: 'offsets'</code> but that doesn't work for me. Any ideas?</p>
  
  <p>PS: I <a href="http://jsfiddle.net/dZYwL/8/" rel="nofollow">created a Fiddle to show the bug</a>. Please, only try that on IE (I don't know why it doesn't work on Chrome/Firefox).</p>