That has been mentioned. It's not a bug. If you click on the thread title, you'll be brought to the first post in the thread (not sure how usefull that is). If you click on the icon to the left of the thread title, it will take you to the first new post in the thread. Alternately, there's a link at the start of a thread with new posts which will take you to the first new post in the thread as well.

Frankly, I like this better. I like having the choice. Besides, clicking on a multi-page thread like this one on the old board never took me to the first new post.