Getting the latest Vagrant & VirtualBox working together

Having trouble getting the latest Vagrant and VirtualBox working together because the ssh key is not acceptable to Vagrant?  Well it turns out that the ownership on authorized_keys is not 600 so it fails in operating systems like Centos.  The trick is to modify one of the files to add a chmod 0600 after the authorized_keys file has been updated.  Full information in the link: