Someone should make a "things not to do unless you really like playing with psql" list, and what to do if you've done them. This is one I've seen, along with accidentally revoking read permissions to the public on the root folder id, since it means you can't even log in once you log out. (THAT one I've seen twice!)
One of the amusing bits of hosting lots of people setting up OpenACS is that I'm starting to accumulate a bit of a list of ways to hose things. Maybe its time to post the list somewhere.