animate Issue in Webkit Browser When View is Zoomed Out

animate Issue in Webkit Browser When View is Zoomed Out

I am new to jQuery and am using the animateTo plugin to animate an element on hover from one size/location to another. When viewed in a Webkit browser at actual size (Safari -> View -> Actual Size) the animation works as expected. However, zoom out (Safari -> VIew -> Zoom Out) and the animation behaves strangely. Is this a known issue, or am I doing something wrong? 

You can see an example here:  http://bit.ly/aSR0rn

I did try the animation using animate directly (without using animateTo), but that didn't make a difference. 

I'm using jquery 1.4.2 min.

This problem does not occur in IE8.