This is for the best, I suspect...
It'll help make a better board.
Here's how:
Apparently, the earlier button checks the oldest thread on the front page, on the bottom. It then jumps to the next older thread when the earlier button is activated.
If I may suggest a "common sense" fix. Have the earlier button search for the newest, undisplayed thread and make it the top of the "earlier" page.
B.T.W. What is the status of the HZ interface code. Can it be shared in a compiled or open source form. If I wanted to set up a board using it, what would that take?