[CentOS] Help with kickstart install

>Really?  I've been doing an entirely network based install, and it doesn't work pointing
>at updates.  Could you post a specific setup that works?

My package selection is the absolute minimum with a few useful tools and a few required
things I know I don't need like firmware yanked. I use a bit of grep etc on `yum groupinfo base`
to figure out what the min requirements are.

abbreviated:

install
url --url= http://ftp.telus.net/pub/centos/6/os/x86_64/ --proxy=http://foo:xx
repo --name=Updates --baseurl=http://ftp.telus.net/pub/centos/6/updates/x86_64/ --proxy=http://foo:xx
...

#%pre
#sleep 999999999

%packages --nobase
# Package Preparation, there is no dns, yum or perl in %pre, deduce minimum package
# selection ahead of time.
...

%post
...