I'm running Chrome on a windows xp machine. If you open a topic and read the unread posts and want to navigate back to board by using either the back arrow or by right clicking and choosing back from the menu that is displayed, one returns to the board under review.
That back navigation does not work when you post a reply. If you post a reply in an existing thread the back navigation, either of the two methods, takes you only so far as the thread as it appeared before you posted a reply (at least I think so, it may go back not all, but display your reply). I noticed this behavior yesterday, and definitely again today. The only way to get back to the board you were reading is to refresh the board by reselecting it.