Can you post some example code that shows your problem?
In the following example the center of the ball on the left is changed in the y value which affects it's rotation:
Code:
import viz
import vizact
viz.go()
ball = viz.addChild('ball.wrl',pos=[-0.5,1.5,4])
ball.center(0,0.25,0)
ball2 = ball.copy(pos=[0.5,1.5,4])
spin = vizact.spin(1,0,0,90)
ball.addAction(spin)
ball2.addAction(spin)