Dell 3000cn Color Laser Printer

Hello, I have a 3000cn Color Laser Printer that has given me no problems. However I do have one small problem that I can't find a solution for. It used to print my pages from page one to the last. Now it prints from the last page to the first. When I have to print a hundred pages it gets to be a real problem. I recently replaced the Print Head Drum. Does anyone know how I can get the printer to print from the first page again? Thank you for any help you can offer.