Below the thread list there is a line "Thread Display Options". It can be collapsed or expanded with a small up triangle at the right side of the line. Within this line there is a drop box "Show threads from the ..." by default it is set to "Last Year" (So you see only 47 of all 69 threads in the Movie subforum). If you set it to "Beginning" you'll see all the 69 threads (It will says that you see only 67 but it is due the fact that there is two threads sticked which are not accounted).