Graham  
The guestbook has been updated to behave more like a guestbook
1/ only admin can reply to posts using the "Guestbook comments" link in the comments section of the control panel
2/ the report spam link has been removed from admins posts and replies
3/ Guest book commenting permissions now have their own settings in the site options
4/ using html you can set comments_disable_links="1" and links will just be text
and badwords="comma,separated,list,of,banned,words" banned words are replaced with ******