As a few of you asked, I have found the "mark forum as read" button. Click on the forum you want to view (ie "Off Topic") and then in the bottom right corner it is at the top of the list of privileges. You have to do it on a forum-by-forum basis I'm afraid.
I hope that's OK for everybody, not ideal but I didn't design the template and it would be too hard to move it.
I hope that's OK for everybody, not ideal but I didn't design the template and it would be too hard to move it.