Rigidbodies Repeling each other?

Hi,

I have implemented player / Horse riding.. Both have rigidbodies & colliders (and their own character controllers, enabled / disabled while riding). I make it ride by moving the player to correct location and then apply a fixed joint. It all works perfectly well, until i decide to dismount. I don't actually move the player away.. Just disengage the Joint, and most of the times it gets off to one side or other. But some times, (Mostly when the horse is walking or running.. but i've seen once while it is stopped also) the player character doesn't just get off. rather it is "thrown" forward, and lands several meters in the front. (But continues working OK after that.. I tried making the rigidbody velocities of both horse & character to 0.. No use.

Any pointers?

Thanks & Regards