getting-started: my kube-dns pod keeps failing

I am just getting started working with stackube.

I am following these instructions for setting up and using a simple AIO devstack setup of stackube:
http://stackube.readthedocs.io/en/latest/single_node.html

I am using ubuntu 16.04 (xenial)

./stack.sh is successful
and everything appears to be working.

Creating a tenant works ... creating the new namespace, the project in keystone and the tenant's default network in neutron.

The nginx and busy box containers can get created.
HOWEVER
1.) i see crashes & restarts of the kube-dns pod, and
2.) 'nslookup' of nginx fails inside of busy box ... i.e. saying it can't resolve 'nginx'
     ( ... so the 'wget -O- nginx' obviously fails as well )

Any ideas on what could be wrong ?

Greg.