Description of problem:
After rebooting, preupgrade does not find its install image and asks me (whatever file I'm supposed to point it to...). This is probably, because preupgrade fails with an exception (but sometimes still presents the "reboot computer now" button):

treeinfo Zeitstempel:Sat Mar 26 01:30:55 2011
/boot/upgrade/vmlinuz Prüfsumme OK
/boot/upgrade/initrd.img Prüfsumme OK
Traceback (most recent call last):
  File "/usr/share/preupgrade/preupgrade-gtk.py", line 797, in <module>
    widgets = PreUpgradeGtk()
  File "/usr/share/preupgrade/preupgrade-gtk.py", line 396, in __init__
    self._do_main()
  File "/usr/share/preupgrade/preupgrade-gtk.py", line 278, in _do_main
    self.main_preupgrade()
  File "/usr/share/preupgrade/preupgrade-gtk.py", line 500, in main_preupgrade
    stage2file = self.pu.retrieve_non_critical_files()
  File "/usr/lib/python2.7/site-packages/preupgrade/__init__.py", line 571, in retrieve_non_critical_files
    self._retrieve_file(self.mainimage, targetdir, reserve_space=extra_space)
  File "/usr/lib/python2.7/site-packages/preupgrade/__init__.py", line 479, in _retrieve_file
    self.instrepo._getFile(relative=fileinfo, local=local)
  File "/usr/lib/python2.7/site-packages/yum/yumRepo.py", line 813, in _getFile
    raise Errors.NoMoreMirrorsRepoError, errstr
yum.Errors.NoMoreMirrorsRepoError: failure: images/stage2.img from preupgrade: [Errno 256] No more mirrors to try.

Version-Release number of selected component (if applicable):
Name        : preupgrade
Arch        : noarch
Version     : 1.1.8
Release     : 1.fc14

(I'm filing this bug on version 14, because the preupgrade already fails on the F14 host system, not only in the rebooted F15/preupgrade environment.)

How reproducible:
Run preupgrade on F14.

Expected results:
I'm expecting preupgrade to find all image files it needs, and after rebooting to find those files as well and upgrade my system.