[Fedora-xen] Paravirtualized on FC5/6 or CentOS4/5 with 64bit hypervisor?

[thewird]

I have 32bit FC7 installed and I replaced the hypervisor (xen.gz) with
its 64bit version by extracting the RPM in order to allow me to see my
28GB of ram. Everything works fine and I can install both 32bit and
64bit FC7's paravirtualized. However, when I try to install (32bit)
FC5/6 or Centos4/5 paravirtualized, it will not work. The VNC windows
doesn't pop up and I notice the guest shuts down. They work fine if
installed as fully virtualized guests as they should. Anything I need
to do to make paravirtualized work with these Distro's? Thanks to
everyone whos been helping this Xen beginner along.

On a side note, when I tried installing FreeBSD 6.2 fully virtualized,
it also didn't work. When I tried installing Debian, the install booted
fine and I was setting up the install when virtmanager complained about
something saying the install didn't work (even though it was running
fine) and closed/deleted the VM.

Marco Jorge