presentation layer current position

Question

Hi, I am using the UIView animation to move a ball. But in some conditions i want to stop the animation in between. And same time i am accessing the position of the ball. But it doesn't give the exact position but the some point behind the actual position.

CALayer *la = (CALayer*)ball.layer;
CGPoint pos = [[la presentationLayer] position];
[ball setCenter:pos];

But it set the image some point behind than the actual end point of animations. So any buddy know does it give actual position or approximate.