Fedora xen - Jun 2007 - FC7 Xen not running properly on HP Compaq dc5750 MT

Hi all,

I have problems running the FC7 XEN kernel (2.60.20-2925.11.fc7xen) properly on
a HP Compaq dc5750 MT machine.
The udev service does not seem to start up, the CDROM is not working and I
receive a lot of  ata2.00 errors, similar to those described here

http://lists.debian.org/debian-amd64/2007/04/msg00016.html

If I am using the latest 2.6.21 kernel (2.6.21-1.3194.fc7) without XEN support
these problems do not occur.

However, this is not an alternative to me, since I need XEN. So what can I do?
Is there a realistic possibility to compile a 2.6.21-1.3194 XEN enabled kernel
or what other solutions to this problem do exist?

Ralf