In JDK1.2beta2, if an activation group becomes inactive, a new activation group
can be created in the VM. This can cause unpredicatable behavior since the
application assumes that all activatable objects created in the same VM will
be re-created in the same activation group. This will not be the case if the
VM's activation group becomes inactive; the objects in the same VM may end up
in different activation groups. Instead of this behavior, it should
be an error to create an activation group in a VM if one has already been
created but simply has become inactive.