Am I imagining things here, or is there a change in behavior?

I seem to recall that when you picked "Mark as Read" for a forum that the page would be returned to the outer layer. (ex: Mark "About BAUT" as read, and you return to "General")

Now it is reterning with that forum.

Not that it really matters to me. It just threw off my rhythm.

It is an extra page refresh since you are most likely to go back after marking an entire forum. It might be bad for someone on a slow line.