iphone animation with UIScrollView scrolling on top

I have a UIView animation which slowly moving around an image (full screen) with various transforms.

This animation of image is like a background.

On top of the animation, I have a UIScrollView, where user can scroll content.

The problem is, if the underlying image animation is going, the scrolling in the UIScrollView is very shaking, not sm开发者_JAVA百科ooth at all.

Any one can help me with that?