Control doesn't work properly in a UITabBarController

[markrickert]

I've initialized my collectionview inside a tab of a UITabBarController and set the RDRStickyKeyboardView's frame to end at the top of the tab bar by doing this:

(RubyMotion code below, but it makes no difference)

keyboardView = RDRStickyKeyboardView.alloc.initWithScrollView(collectionView)
keyboardView.frame = CGRectMake(0, 0, CGRectGetWidth(self.view.frame), CGRectGetHeight(self.view.frame) - self.tabBarController.tabBar.frame.size.height)
keyboardView.autoresizingMask = UIViewAutoresizingFlexibleHeight|UIViewAutoresizingFlexibleWidth
self.view.addSubview(keyboardView)

And I get the control as expected above the tab bar:

However, when dismissing the control, it goes OVER TOP of the tab bar (out of its defined frame) as illustrated here:

Any idea why this is happening and how i can make it look better on a UICollectionView contained within a UITabBarController?