I have been using my 2006 2.0GHz white macbook for a lot of patents viewing on Preview. However, I have been pretty much annoyed by the very non-smooth and laggy of the patents pdf files viewing on Preview. I wonder if this problem originated from the processor's speed or the graphic card? I am planning to buy a new macbook pro and most probably the 2.53GHz one. I really wondering if the same problem will appear in the new macbook pro or not, as since I have to view a lot of pdf and hence smoothness on Preview is an inportant issue to me. Thanks.