title: kendo dropdown Ipad issue
body: <p>I'm working with kendo 2014.1.318 in an asp.net MVC application : I use the wrappers.</p>
  
  <p>I have an issue with the cascading dropdown on Ipad (IOS 8.1 safari)</p>
  
  <p>The issue is not reproducible on an android tablet and on windows browsers, I tried ie9, chrome, firefox and safari for windows : no problem</p>
  
  <p>So, here is the problem:</p>
  
  <p>I have a first dropdown containing a list of brands.
  I have a second dropdown with a list of models</p>
  
  <p>First I select a brand 
  My dropdown "models" is populated => ok</p>
  
  <p>Then I select a brand with a few models</p>
  
  <p>My dropdown "models" is populated but the popup is not painted: it's all white </p>
  
  <p><img src="https://i.stack.imgur.com/vUanC.png" alt="enter image description here"></p>
  
  <p>But if I touch the popup a few time: the items appears</p>
  
  <p>If I select a brand with a lot of models : no problem</p>
  
  <p>So I think this issue only appears when the number of items in the "models" dropdown is not big enough to activate the scroll in the popup</p>
  
  <p>Has anyone experienced this issue?</p>
  
  <p>Do you have any ideas how to resolve this ?</p>