Center of mass

Hi Guys!
I found an article which describes how to use the center of mass http://code.google.com/p/jbullet-jme/wiki/CenterOfMass
Yes, it really works, but only if the item is on the ground. In flight, it also flies directly.
My mission: to make sure that the object was flying until begins to turn, by the center of mass.
Can anyone knows how to help me?

P.S. sorry fo english, i use translator.

No I did not properly set the task.
I need the item to the right place is always falling down, like a cat on his paws.

I have no idea what you are asking. I guess you’ll have to find a better translator…