title: UIButton is not clickable when it's on top of a MapView
body: <p>i've searched for quite a bit of time but so far I couldn't find the exact problem.</p>
  
  <p>I've created a mapView in InterfaceBuilder. Trough the click of a button I add another View.</p>
  
  <pre><code>self.buttonView = [[ButtonView alloc] init];
  self.buttonView.backgroundColor = [UIColor whiteColor];
  [self.view addSubview:self.buttonView];
  </code></pre>
  
  <p>In the created buttonView, I create 5 buttons programmatically, like this:</p>
  
  <pre><code>UIButton *button1 = [UIButton buttonWithType:UIButtonTypeRoundedRect];
  button1.frame = CGRectMake(25, 275, 100, 30);
  [button1 setTitle:@"button1!" forState:UIControlStateNormal];
  [self addSubview:button1];
  </code></pre>
  
  <p>The buttons appear correctly, but they are not clickable. I've tried several things,but nothing seems to work so far. 
  Whenever I click on a button, the mapView gets clicked. For example when I double click a button, the mapView zooms in. Both mapView and buttonView are subViews of "view".</p>
  
  <p>I want the buttonView to be on top of the mapView (which it does) and the mapView to scroll underneath the buttonView (which it does), while the buttons stay where they are (which they do), but they are not clickable</p>
  
  <p>Help is greatly appreciated! :-)</p>
  
  <p>EDIT1: Tried <code>self.buttonView.userInteractionEnabled = YES;</code>- doesn't change anything. (also for the buttons themselves!</p>