how to keep object from rotating with its parent?

So basically… How do you keep an object from not rotating even if its parent is rotating?

See it this way: I have a ball. A normal ball that is supposed to roll.
For graphics purpose, I need to put a ring halo around it. You know, the thing above an angel’s head. I also need this halo to remain horizontal. So I make an alpha-plane and parent it to the ball. I set the alpha plane as no collision.
The problem is that when the ball rolls, the ring effect thingy spins with the ball. I Tried setting the plane as a billboard (however that is spelled) , but I stop seeing it at all.

Another thing you need to know is that the ball is supposed to be spawned using the add object actuator.

Can someone please help me?

for the 1,354,534 time: use Vertex Parenting!
Select your object, enter Edit Mode, place a new vertex at the centre of the object, then select it and the child object ( press Ctrl key while selecting), do Ctrl-P to make Vertex Parent!