PDFpen gives you several different ways to move through a PDF document. How they work sometimes depends on whether you have enabled continuous page display (see the section just above).
Here are the ways to move from page to page:
Toolbar Up/Down controls: Click these to go to the top of the next or previous PDF page when continuous page display is disabled. When continuous page display is enabled, these move the display up or down a screen, regardless of page boundaries.
Go menu: The Next Page and Previous Page commands move the display up or down a screen, regardless of page boundaries when continuous page display is disabled. These commands also move by screen when continuous page display is enabled and the page is too big to fit ...