When reading forums with the "unread" option selected, the server returns threads that were already revealed the first go around. See snapshots below....
Initial view - note I am showing 20 as the starting number and fist post is from DorminWS (Homesteading as prepping / 13 minutes ago)

Second view, scrolled to the bottom, shows JustInCase (Sneaky piano teachers / 19 hours)

Refreshed, starting number is 40 and and you will see that right after JustInCase's post of those sneaky piano teachers, DorminWS is back in the game showing the same post (now 14 minutes old).
