Problably you'll be able to fix missing collision behaviour (eg. when 2 meshes are moving towards eachother!) when you add an "updateworld(0)" after every parties moves. I mean, when you have 2 spaceships and several asteroids and you only want to check if a ship collides with an asteroid, but don't care if asteroids collide correctly with other asteroids, or ships collide correctly with other ships, you would have to move all asteroids, then updateworld(0) then move all ships and then do the updateworld() as usual.