Jeezz, I've got 116 pages to get through.....someone will probably hit me with Thread Necromancer tag if I start replying.
If you have pressed the "Mark all as unread".....-mouser
I think if there was a button marked that you would end having
every post marked as unread.....it would make my 116 pages look like a Sunday afternoon book.
Possibly
Mark all as Read is what you meant
Addendum: OK, that's strange - I had 110 pages, I selected all the threads on the last page (110), and then clicked
Marked Selected Read. I then had 1 page with 6 threads, refreshed it twice, still the same - refreshed again and I'm back to 109 pages.