Here are the exact symptoms of the problem.  I will often turn on the forum and find it locked on a page.  It can access pages below that page, but not pages above it.  If the page is not full at the time, it will accept new posts on that page until it fills up, but it will not advance to the next page.  Typing the next page by hand will not allow it to advance.

An example is when it gets stuck on page 4510.  There are posts on pages 4511 and 4512, but they cannot be accessed except directly by Active Posts and topic/post histories of individual members.  It will access any page up to and including 4510.  However, when I type in "4511" or "4512" in the box, it goes to page 4510.  This persists even if I close out the window and re-enter in a new window, sign out and sign back on, or push refresh on my computer.  Even when I restart my computer, it can be several hours out of date, or even a whole day.

Then, at random, it will finally update.  This is not predictable, and when it happens, I have access to pages up to and including 4512 (in this case, that is the highest page with posts).  But, then when page 4512 fills up and posts go to 4513, I have the same problem again.  This time, it returns as the default page 4512, and typing "4513" brings up page 4512 instead.  The updating process is slow, and usually returns a whole day of posts that are hidden because it will not update.

All the sections are having this problem.  Aside the Friends section, it is usually less noticeable on other sections since they don't usually fill a whole page or more in a day.  They might only have 4 or 5 new topics per day, and might take a couple of days or more to fill the page.  However, if it does fill the page, it will be stuck on the previous page until the Great Updating happens.

Hopefully, this helps someone locate the cause of the problem and fix it.