I can't tell you what happened but not to long ago every time I went to read a second page to a thread the screen jumped down to the bottom & & I had to click on the "top" tab to get back up to the current post (or scroll up). It finally somehow corrected itself & now it's working fine. I thought I had accidently changed some sort of setting. But I guess it was just a computer glitch. You might try contacting administration & see if they have a solution.