First, thanks very much for this plugin, it was just what I needed.
I did have an issue with logging out. I downloaded version 2.1 and found that when I tried to log out I got the dreaded "Are you sure you want to do that?" screen. After poking around for a while I found that I had to edit out the check_admin_referer('log-out') code. I think the log-out nonce was introduced in WordPress 2.7 rather than 2.6.