Finally upgraded to Mountain Lion and I am noticing an annoying behavior in Preview. When I two-finger scroll too quickly with my 2009 MBP trackpad, the scrolling is jerky and can skip many pages in a document. So you're scrolling a 25 page document, you are at page 2, you scroll quickly to get to page 10 and suddenly you are page 22... I cannot replicate this with a mouse no matter how fast I scroll and I don't see a setting for trackpad scrolling speed. Slowing down the tracking speed of the trackpad seems to have no effect either... I have secrets installed but I can't find a hidden preference there either... Anyone else experiencing this? How could I fix this? Thanks in advance ! EDIT: I also had the smooth scrolling disabled (thanks John Siracusa!) via but turning this back on has no effect on this behavior. My setup: 2009 13" MBP with 10.8.2. Full disclosure, this is a cross-post from StackExchange.