Comment 4 for bug 44402

This problem is still current today.
If you entered the realm when prompted during the interactive portion you can run

kdb5_util create -s

Without any further arguments.

I got my initial config info from http://www.alittletooquiet.net/text/kerberos-on-ubuntu/
This article has a couple problems (I have emailed the author) but is helpful nonetheless.
You need to run the create command before restarting the daemons, which the author doesn't know until he reads my email. :)
Anyway I just updated and installed a few minutes ago and this bug is still active on 7.10.