I read all on Firearms earlier this morning.  Just went back to read all again and there were three new messages for me.  Found only one when reading all so I click read all new to me afterward and found two more from a day or two ago I hadn't seen.  I can't imagine how these were not shown to me before under the new system.  I always do a "read all" anytime I visit the Discussion page, and I don't recall any of those anomalies where I am in the middle of reading and the new message number at the top changes to zero in the last couple days.