Binding to zoom

Question

Hi,

I have two buttons - in and out - created in WindowsForms
When these are clicked they called a method within my hosted usercontrol - zoomin and zoomout.
In my usercontrol I have a property - zoomlevel - which is increased by 0.1 and decreased by the same once these buttons are clicked.
I then have the property zoomlevel bound to the scaletransform of my entire usercontrol - <ScaleTransform ScaleX={Binding Path=ZoomLevel} ScaleY={Binding Path=ZoomLevel}

Though nothing happens, and ideas?
Though when I bind the scalex and scaley to a slider value within the same usercontrol, applying the same logic it works perfectly!

Urema.