I don't know if this is just Firefox or if it's to do with windows, but whenever I right-click in an internet window, if I don't immediately get my cursor to highlight what I need, the right-click inset automatically scrolls down to a completely blank area, and seems to continue to do so until I take the cursor off. I can't scroll back up; the only way I've found to "reset" it is to do ctrl+a and then try again.
Can anyone tell me what I did? I haven't downloaded any new add-ons or anything . . . it's pretty strange!