Fedora xen - Jul 2006 - Xen high memory usage/X programs running poorly

''xm top'' shows Dom0 to be using 2846916k of memory (about 90.5
%)
''free -k'' shows Dom0 to be using 447192k of memory
''uname -r'' shows 2.6.17-1.2157_FC5xen0
X programs running over ssh are extremely slow (such as 
http://virt-manager.et.redhat.com/ and http://xenman.sourceforge.net/) 
to the point where they are mostly unusable.  When using the non-xen 
kernel, X programs seem to run fine over ssh.

I did a standard install of FC5.  I changed the size of / to 20gb so 
that I could create other LV for the domUs.  I installed the basic 
webserver package to start off with.  I installed http://webmin.com/ to 
make it easier to configure the iptables, and switched ssh to use a 
different port.  I then ran ''yum update'' and disabled SELinux
by editing
/etc/selinux/config and setting SELINUX=disabled.  Lastly, I set 
''DEFAULTKERNEL=kernel-xen0'' in /etc/sysconfig/kernel
and installed the xen kernel with ''yum install kernel-xen0'' as
directed
by http://fedoraproject.org/wiki/FedoraXenQuickstartFC5 and rebooted.

Am I missing something that is causing memory usage to be so high and 
causing X programs to run so poorly?

Paul Traylor