The dashboard is meant to be used as a presentation tool, and therefore, it is by design that it will only print what is in the view. One option may be to change the size of the dashboard, separate the dashboard into multiple dashboards or print out the sheets.
This might be a good one to place in the Ideas section!
Do you know if there are any plans to adapt/extend dashboards to be used as a publishing tool as well as a presentation tool?
Views generate PDFs reasonably well, but dashboards are really hit-or-miss. It would be great if dashboards could be used for publishing.