When printing are you seeing a faded print out such as mysterious white lines that have appeared, this problem could be caused by clogged ink jet nozzles. This doesn't mean that you have to throw away that expensive print cartridge, there are few things that you can do to help correct the problem.
Some printers come with a nozzle-check utility to make sure that there are prevent and remove clogs. These utilities are far from perfect but worth checking out. This option is generally available as an application that cames with your printer, or is part of the printer driver. See your printer's manual for more information.