Of course, you are right! Xen is on top of fedora
Sorry my translation skills betrayed me! :-)
Same error again!!! :-( Lets try with a diagram:
+------+ |FC5 | +------+ |XEN| +------+- | HW | +------+
FC5 on top of Xen FC5 on top of Xen FC5 on top of Xen FC5 on top of Xen FC5 on top of Xen
Sorry :)