Sorry for not noticing your post.
Any suggestion on how long the logon expiry should be set to, or what's the maximum time you'll need to edit an article?
I know that having a session expire in the middle of an edit is one of the biggest frustrations working on a wiki. On the other hand, the session timeout is supposed to reduce the chance bogus edits when a registered user has left their terminal unattended.
Assuming the likelihood of the latter is small, I will try setting the session timeout to 15 minutes unless there is a better suggestion.