I tried hitting enter several times but it never moved past.
After spending a day of frustration I really think it something to do with creating the repository metadata.
If I take the contents of a rhel 6 iso and add it to my pxe server it works. You can boot to the PXE and install. The problem occurs when I add a custom group to the comps.xml and run createrepo to regenerate the repo metadata.
My PXE server is running rh5 and I was using the createrepo tool on it for the rh6 kickstart.
But I found in the rh6 deployment guide that will not work. Full explanation here
So I built a rh6 system, ran createrepo there and moved everything back to my rh5 pxe server and I got the same result.
What am I missing?