Trouble Moving Origin

I need to move an object’s origin to where the cursor is without moving the object. When I do Object => Transform => Origin to 3D Cursor the object moves instead of its origin. This is contrary to my prior experience and all documentation I can find.

Furthermore, when I numerically enter a new coordinate in the Transform Panel’s Location fields, the object does not move which makes it impossible for me to precisely position the object.

I need to know why the above is happening. I need to place the object’s origin in the center of the ring, and have that origin on the centered 3D Cursor. The file is at:
http://www.pasteall.org/blend/29091

Is this a Blender bug or is there some setting or configuration I do not know about?

Remove the rigid body physics then move the origin

That did it, thanks! :slight_smile: