title: Combo box issues in IE
body: <p>I'm using Sencha 4.1.2a, IE 9.</p>
  
  <p>I'm in the process on migrating my company's project from sencha 4.07 to sencha 4.1.2. </p>
  
  <p>I'm now face with unexpected problems with combo box. We have extend the combo box in order to respond to our needs.</p>
  
  <p>First they are really slow, but only on IE (Currently using 9, but changing browser mode doesn't seem to have any effect...). I can't recreate this issue in both Chrome and FF.</p>
  
  <p>Second, the first n items on the combo box appear ok, like this:</p>
  
  <p><img src="https://i.stack.imgur.com/80DJS.jpg" alt="enter image description here"></p>
  
  <p>But soon as i scroll down this happens:</p>
  
  <p><img src="https://i.stack.imgur.com/i5jVT.jpg" alt="enter image description here"></p>
  
  <p>And only when i hover above the items, do the items "return" to their position. But only the ones rendered in the first place, since the other items bellow are never render. And then i end up with this:</p>
  
  <p><img src="https://i.stack.imgur.com/O64sh.jpg" alt="enter image description here"></p>
  
  <p>I thought this was related to some changes made in the newest version of sencha (that meant changing our own code), but the fact that it runs ok in the other 2 browsers seems to point to the fact that the problem is with IE...</p>
  
  <p>Any thoughts on why this happen?</p>
  
  <p>Thanks in advance!</p>
  
  <p><strong>UPDATE:</strong> </p>
  
  <p>I found out the problem. </p>
  
  <p>It's the css class 'x-boundlist-item' which has css3 properties. </p>
  
  <p>My question now is how to prevent/disable sencha from using CSS3 (if possible)? </p>