This suggests that your filesystem isn't labeled. Touch
/.autorelabel and reboot, or manually boot single-user and
run /sbin/fixfiles relabel.
Did you install with SELinux enabled, or try enabling it
later? How did you enable it?
It is a fresh install of FC3, installed with targetted as default policy. I.e.
I have changed nothing since the install (except updating rpms with "yum".
Is there some doc on what relabelling means?
Ruth