General annoyance bug perhaps.

I find that whenever something collides with something else at fast speeds, they sometimes get stuck together and cause problems.

its especially evident when a fast moving projectile hits a stationary (mass 0) object.

is there any way to stop this happening ?

I think you just need to use setContinuousCollisionMode(1) in your bodys (or in your materials)

i am already doing that, and it still occurs

Perhaps you can add some elasticity (or increase the existant one) between the objets to make them to repel together.