OnTriggerEnter fired incorrectly (android device only)

Hi

We are facing a strange issue when testing our game on Android 4.1.2 (device is a motorola XT925 razr/r HD). We use unity 4.3.2f1.

We have a pendulum: a hinge joint connected to a model (a tube) connected to another model (a box) through a fixed joint (so the tube can rotate around the hinge joint, and the bow will do the same). Both models are in a parent object. The box object has a collider isTrigger on with rigidbody on it (with gravity).

The player is attached to a charactrcontroller and has some istrigger colliders in sub objects. On windows, everything is fine. when the pendulum touch one of the collider of the player, OnTriggerEnter is called (on the pendulum box). On the moto device, sometimes ontriggeriscalled with no reason (the pendulum is far away from the player. Visullay the pendulum is moving fine, but logs indicate ontriggerenter with the charactercontroller).

It looks like a unity bug, but did someone faced the same issue? is there something we could do to workaround easily ? how to debug it as it doesnt show on editor?