Animation Windows Phone

Hi,
my problem is resizing UIElement that is animated with Storyboards.

I want to render View from Shared Code as native FrameworkElement in Windows Phone part of the project. My Windows Phone class is derived from ViewRenderer<...>

Steps:
1. OnEelementChanged(...) is called,

1. Now I am making ellipse shape that will call function related to Storyboards,

3.Method: public Storyboard CreateAndApplyStoryboardHeight(System.Windows.Shapes.Shape component, int valueMin, int valueMax, float height){...} which should animate values From = height + valueMin, To = height + valueMax

(Same function for width)

PROBLEM: Animation works just fine, but I am unable to set ellipses width and height (simulates radius changes), actually everytime I do that, after screen orientation, size is fixed, but I need it dynamic. I need it to follow values that are related with layout calculations. I tried to reach those information but they are NaN. Tried with ActualWidth and ActualHeight, with adding Grid and calculating it's dimensions, but still nothing.

Any help?

Thanks