I seem to have found a bug in Flash Pro CS5.5. When a Spring setting is applied to the first bone in an armature over a shape (all bones have spring as well), the armature cartwheels, and catapults all over the screen.
I learned of this bug from my schoolwork with Classroom in a Book for Flash Pro CS5. The Problem persists with Flash Pro CS5.5. Who ever knows how to report bugs, please do so for this.
This is what happens if one publishes the demo version, as well.
Also, it seems that gradient fills vanish when the armature is setup.
I hope there is a work around.