can't make moderated list unmoderated

With Mailman 2.0.8, I made a list moderated (by
setting "Must posts be approved by an administrator?"
in Privacy Options) to "Yes". A few weeks later, I
changed my mind and set this to "No". However,
whenever someone tries to post to the list, I still
receive a message from Mailman, saying that the
posting requires approval (the subject line
says "Posting to a restricted list by sender requires
approval").