Camera will look away from current position without reason

When your character looks in some directions (e.g. you look straight down and then right) the camera will turn upwards for no reason. I seem the only one experiencing this issue, though, and I've tried installing other Linux distributions but it still happened, and it's not the mouse, either, since it happens when I use my laptop's touchpad, too. Although a friend of mine has Lubuntu and she doesn't have this issue.