Print window javascript only prints a blank page.

As suggested by many, I've tried using the "window.print();" javascript to print a single page of my course.It speaks to my pinter, but it only prints the info from the actual web browser (date and window name at the top, web address and page number at the bottom) Here is a screenshot of exactly what prints:

Has anyone else experienced this issue? I can't figure out why this worked so well for others, and not for me. What could be interfearing with the print?