Why can't I use the boolean modifier on more that two objects before it fails? I am trying to take a cube and multiple spheres and subtract each sphere from the cube. I have been using the boolean modifier to archive this, but it seems to fail after just two spheres and the third one just cut out without the embedded spherical shape.

This can be seen here:


Why is this happening?
Try joining all the spheres into 1 mesh and just using that as the boolean object