Hidden MeshCollider re-enabled after rotation?!

Hi, I’m doing picking on a complex object like an onion where there are meshes enclosing other meshes etc. When I’ve hidden the top layers by disabling renderer and colliders I can pick the meshes now shown. However when I rotate the object, somehow the top layer’s collision mesh gets re-enabled automatically. Is this a behaviour of Unity?

I know it is enabled because i enabled gizmo rendering for the colliders and when i rotate voila, the top layer’s collider becomes visible! Grrr

Seems to have been fixed by Unity 4.3