It's my understanding that if you haven't viewed a thread before, it will take you to the first post. However if you have viewed a thread, it will take you to the first unread post.What I really dont like is that when I click on a thread on the main page, which I have not ever read, it takes me to the last post in the thread, and not the first unread post which would be the first one. Could we change this?
Are you clicking "Mark Forums as Read"? If so, then you are telling the forum you've read all the posts, and it will take you to the first unread posts in each thread next time you visit.