slow starting X
I had a similar situation. I was boggled about the solution and had nearly given up but then I found what I thought might be solutio and sure enough, it was. If you add the option
Option "NvAGP" "0"
to your XF86Config it should work. It worked for me. I had tried everything. Including
Option "IgnoreDisplayDevices" "DFP, TV"
that one did not work for me. The "NvAGP" worked great. Try it. If it works for you then great!