Weird issue with scrolling/Page down

[Lseadragon]

When I'm scrolling down pages using the highlighted bit of the text, when it reaches the bottom of the screen it suddenly jumps down to the end of the page, skipping over the rest of it (an annoyance in reading forum threads). Similiarly, the page down key skips down to the bottom instead of just a page, and the page up key does not work at all. The only way to do it is to use the sidebar and click down. Does anybody know why this might be happening?

[Marvo]

What browser and what OS?

[Lseadragon]

What browser and what OS? Oh, I am a derp. Nevermind this question.