My dock is vertical along the right side of my screen, my 'downloads' stack is set to 'date added', 'stack', and 'grid'. Quite often the icon of the next to last item downloaded is larger than all the others. The size difference goes away if I click away from the stack and open it back up, but it's a little aggravating. Anyone have any ideas what's going on? Here's a pic... blurred for your protection!