Scratch

When I don't log in to the forum and select Show Recent Posts (or words to that effect), all of the boxes on the left of the page are light blue.

When I log in and select Show Recent Posts, some of the boxes are light blue and some are dark blue.  Generally, the ones that I read on some previous visit are light blue and the ones that have been created or updated since the last visit are dark blue.

When I click on an unread (dark blue) thread, navigate to the thread, and hit the back button to return to the list of threads, that thread has not turned to light blue even though I just accessed it, read it, and returned to the list of threads.  I would expect it to turn light blue and to stay light blue until the next time it is updated.

Is this normal, or am I doing something wrong?  I asked this question once before, but the answer that I got was so much at odds with what I have come to expect that I am asking it again.  The question in brief is:

Shouldn't the big square turn from dark blue to light blue when you navigate to the thread page and then return to the list of threads without any requirement to log out of the forums and then return or to click the button to "Mark all threads read."  If it is not automatic, is there a way to mark threads as read on an individual thread-by-thread basis?