Whenever we print a PDF on our Phaser 7500DT, the images and text are very light, almost impossible to read sometimes. However if you save the PDF as a jpeg and print, the quality is perfect. The problem seems to only be with PDFs. I've tried multiple computers, updating the driver, changing the print settings, replacing the black toner and imageing unit, nothing seems to change the problem (but again it's only a problem when printing a PDF).
Printing the same PDF to a non xerox printer works perfect as well, so I'm assuming it's a driver issue, but I don't know what else to do at this point.