why did FC6 install a XEN kernel on my inspiron?

[Robert P. J. Day]

  i just finished installing FC6 over top of my LVM FC5 filesystems (leaving /home where it is, of course, as i have done numerous times), and what i just saw at first reboot was a XEN kernel, the booting of which ended badly with

  "cannot execute a PAE-enabled kernel on a PAE-less CPU!"

there appears to be nothing in bugzilla related to "pae-less cpu", and a google search turned up a couple web pages that, so far, have refused to load.

  i'm open to suggestions.  this was on an inspiron 9200, for which i've never had a problem loading and booting fedora core based on the initial install.

rday