rotation-driven loc-Animation: missing part depending on degree of rotation

Dear forum,

I try to achieve the impression of a long flexible pole (imagine fiberglass for example), lower end fixed on the floor, upper end not fixed but forced down to the floor to one side, so that the pole is bent to its maximum as the starting position of my animation. Then the fixed end is set free, so that the upper end is swinging back an forth until it comes to a rest position (standing straight).

I found the following solution that works fine except for unexpected behaviour concerning one aspect:
The “pole” is an armature with IK consisting of one straight line of bones, the target is an empty that has a “clamp to” constraint so that it moves on a curved nurbs path when changing it’s x location.
The empty’s x location is driven by a “rigid body physics pendulum” which means the y-rotation of a rigid body cube serving as the pendulum drives the empty’s x-position. This works as a physics-fiberglass-like animation of the pole.
What’s wrong:
Depending on the starting angle I choose for the pendulum, part of the x-movement of the empty is missing. There seems to be a certain angle which must not be exceeded, but I cannot figure out why.

schwankender Mast.blend (553 KB)

I would be glad if someone could have a look at my .blend and give me a hint.
When you start my animation with ALT-A, you will see the missing part of the desired movement very short after the beginning. The whole rest is “normal” as desired.

Thank you in advance

I have never had successful results using the rigid body features (which work in the game engine) and simultaneously using armatures for the segmentation of object’s structures. since you using just a cylinder forget the bones and IK side of it and make the soft body affector force work on it, or if the target is for the game engine then drop the bones and any ik handles (since the ik goal feature doesnt work in the game engine) and use the rigid body property by itself. actually the rigid body effects from the game engine can be baked to the keys in the scene so this is a good solution for both (recording in the editor and using the game engine)