title: UITableView hangs for 5 seconds between heightForRowAtIndexPath and cellForRowAtIndexPath
body: <p>I have an extremely weird behavior here. I'm using RSSKit to download and parse an XML-Feed. So far so good. That happens during a few milliseconds. After thats done I call reloadData on my TableView. Immediately thereafter the numberOfRowsInSection and heightForRowAtIndexPath calles in. Then there is nothing happening for about 5 seconds. Only after that 5 seconds cellForRowAtIndexPath gets called.</p>
  
  <p>And it gets even more weird! During this period when nothing is happening, the tableView is already completely responsive. When interacting with the UI cellForRowAtIndexPath gets called immediately.</p>
  
  <p>Placing a setNeedsDisplay on the tableview directly after the reloadData doesn't change anything. I assume this issue seems to be connected to the Window-Server of iOS?</p>
  
  <p>A small summary how it appears to me for now: The update process of the UI seems to not react for about 5 seconds while the phone is doing nothing.</p>
  
  <p>Anyone any idea how this could be tracked to a cause?</p>