title: UITableView with transparent cells overlap old cells when reloading data
body: <p>I have a UITableView with a transparent background color and cells which also have a transparent background color. When I reload my tableView with:</p>
  
  <pre><code>dataSource = some new data
  tableView.reloadData()
  </code></pre>
  
  <p>I can see the new cells overlap the old ones.
  <a href="https://i.stack.imgur.com/x225W.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/x225W.png" alt="transparent cells overlapping each other"></a></p>
  
  <p>I did try to use use</p>
  
  <pre><code>tableView.beginUpdates()
  // remove all rows here
  change data source
  // insert new rows here
  tableView.endUpdates()
  </code></pre>
  
  <p>but it did not work. I tried as well <code>tableView.reloadRowsAtIndexPath(...)</code> but still no luck.</p>
  
  <p>And finally I set all my cells and my table view to clear graphic context when redrawn but it did not manage to fix this issue.</p>
  
  <p>Any help would be greatly appreciated.</p>
  
  <hr>
  
  <p>My cell creation function:</p>
  
  <pre><code>override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -&gt; UITableViewCell {
      let cell = tableView.dequeueReusableCellWithIdentifier("suggestioncell")
      cell.backgroundColor = UIColor.whiteColor().alpha(0.1)
      cell.textLabel?.text = (suggestions![indexPath.row] as! SVPlacemark).formattedAddress
      cell.clearsContextBeforeDrawing = true
      cell.contentView.clearsContextBeforeDrawing = true
      return cell
  }
  </code></pre>