[away3d] How do you tell an Object3D its matrix is updated?

[John Brookes]

Away3.6
Just as an example say you have a cube c and add the following in the enter
frame

trace(c.transform.rawData);
matrixComponents = c.transform.decompose()
matrixComponents[0].x += 1;
Matrix3D(c.transform).recompose(matrixComponents)

The above should move just the same as c.x +=1
but it doesnt move even though the matrix is changing

A hack is to do
c.y+=0.1
c.y-=0.1

Then the cube moves.

Better way?