Foreground printing
One possible cause for printing errors is from using Apple's Desktop printer. If you are having printing problems, yet that printer has been working before, one possible solution is to turn background printing off. Here is how you turn it off, using either the LaserWriter 8.5 or 8.6 drivers:
First, choose "Background Printing" from the pop-up menu in the upper-left hand side of your window:
Then, check "Foreground (no spool file)". If you want, you can click "Save settings" to make the printer use foreground printing as a default. (You can always change it back, if you like.)