i agree with the above. The last page feeds a bit differently than the ones before it, because the beginning of the paper-feed system is still after the last page starts feeding. So, you might have something sticking in the paper path, or something slipping.
If you want to try, you can open some fresh paper and load it. Then adjust the humidity adjustment to correspond to humidity in the environment. Removing and reinstalling the printer in Windows, or whichever OS, can work the gremlins out :-).
If you've used up more than one drum unit, replaceable parts may be at fault. But my first guess is humidity and old paper.
Does itnever double feed or jam? Did you look in CenterWare at the Alarms. Might find clues there, but only if it's connected by Ethernet (RJ-45 plug), not USB. TRY some of those things. Printer after printer, model after model, the common problems are the same.
