Is this a bug in Matrix3D.interpolate?

I guess it is.
For my attempt at a workaround see http://wonderfl.kayac.com/code/5587dec25ecd87aff4b7670f42352c61dcbb11c5
According to http://livedocs.adobe.com/flex/3/langref/flash/geom/Matrix3D.html#interpolate()
.
"[Matrix3D.interpolate] simplifies the interpolation 
from one frame of reference to another by interpolating
a display object a percent point closer to a target
display object. The result is a new Matrix3D object 
where all the elements for the translation, rotation, 
*and scale* are interpolated to values between the 
current display object and the target display object."
.
It seems to ignore the scale. Am I missing something?

