title: UIMenuController does not show on iOS 4, but works on iOS 5
body: <p>In a custom view i have set 'canBecomeFirstResponder' to return YES
  and have also defined '- (BOOL)canPerformAction:(SEL)action withSender:(id)sender'</p>
  
  <p>I use the following code to display the popup menu:</p>
  
  <pre><code>[self becomeFirstResponder];
  UIMenuController *theMenu = [UIMenuController sharedMenuController];
  
  
  if (theMenu.menuItems==nil)
  {
      UIMenuItem* item = [[UIMenuItem alloc] initWithTitle:@"Open" action:@selector(openAction:)];
      NSArray* array = [NSArray arrayWithObject:item];
      theMenu.menuItems = array;
      [item release];
  }
  
  CGRect rect;
  rect = CGRectMake(self.frame.size.width*0.5, self.frame.size.height*0.5, 0, 0);
  [theMenu setTargetRect:rect inView:self];
  theMenu.arrowDirection = UIMenuControllerArrowDown;
  [theMenu setMenuVisible:YES animated:YES];
  </code></pre>
  
  <p>The problem is that this works fine on iOS 5
  but doesn't show anything on iOS 4.3.</p>
  
  <p>However on BOTH iOSes the 'UIMenuControllerWillShowMenuNotification' 
  and the 'UIMenuControllerDidShowMenuNotification' notifications are received
  as expected.</p>
  
  <p>Can anyone help or point me to the right direction please.
  Thanks in advance.</p>