Modal view being displaced
<p>I have the following code to show a modal view which is added as a subview of my tabBarController. However despite using the autoresizingMask property to allow for when an incoming cellular call interrupts my app and shows the green status bar at the top, i find after this event the whole view is displaced by 20 pixels downwards</p>

<pre><code>    - (void) showLogin:(UIView*) modalView
   {
     CGPoint middleCenter = CGPointMake(160, 226);
     CGSize offSize = [UIScreen mainScreen].bounds.size;
     CGPoint offScreenCenter = CGPointMake(offSize.width / 2.0, -210); // start from top
     modalView.center = offScreenCenter; // we start off-screen
         modalView.autoresizingMask = UIViewAutoresizingFlexibleTopMargin;
    [self.tabBarController.view addSubview:modalView];

    // Show it with a transition effect
    [UIView beginAnimations:nil context:nil];
    [UIView setAnimationDuration:0.4]; // animation duration in seconds
    [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
    modalView.center = middleCenter;
    [UIView commitAnimations];
   } 
</code></pre>

<p>How to solve this?
Thanks</p>
