Scrolling down to the end of a document always have its last page sticking to the lower edge of the window. You have no room left below to keep a comfortable view on the doc.
So the trick is simply to double-click on the last page icon of the Layout palette so that page comes in the upper left corner of the window and you get room below to center the page by scrolling or dragging the page.
Hope this helps!
Jean-Marie Schwartz
> Mac Pro Quad Core Intel 2.8 GHz, OS X.6.8, Quark XPress 9.2, Adobe CS5 <