I feel like since the 10.7.3 update I've been having fits resizing windows manually. Today I finally figured out what the deal was. Using the track pad on my mid-2010 MBP I have to place an inordinate amount of pressure on the track pad with my dragging finger while depressing the left-click area in order to resize windows manually. Has anyone else noticed this? The same is true with highlighting multiple files via click/drag selections. It is like the track pad has become less sensitive.