The init script explicitly checks for a database file or pretend the db_library to be kldap. I have a custom driver and the check fails. At most the kadmin init script may check if db_library is present w/o trying to guess what value it should be set to. But most probably it would be better to skip the check altogether and let kadmin log in /var/log/kadmin.log that there are errors. The situation is particularly hard to discover because the initscript output is completely suppressed in F15 when systemctl gets involved. I had to run it with SYSTEMCTL_SKIP_REDIRECT=1 to finally get the error and find out what was going on.
krb5-1.9.1-12.fc15 has been submitted as an update for Fedora 15. https://admin.fedoraproject.org/updates/krb5-1.9.1-12.fc15
krb5-1.9.1-16.fc16 has been submitted as an update for Fedora 16. https://admin.fedoraproject.org/updates/krb5-1.9.1-16.fc16