I have a late 2008 unibody macbook pro. When i use expose to show all windows or the hot corner to show my desktop the animation is no longer smooth. The windows aren't jagged but they just don't scale smoothly like it used to around 3 days ago. As far as I remember I haven't changed anything. About 3 weeks ago I upgraded my macbook to 8gb ram from 2gb, everything went well despite reading some people having issues with the early umbp freezing up with 8gb ram. I have never had this freezing issue so I don't think the ram is causing the lagging. I've resetted my pram with no avail.