printer prints mirrored negative images

I have an HP Laserjet 4200 that suddenly started printing strangely from one of the several Windows XP computers that prints to it. In Outlook and Internet Explorer, any documents printed come out with black paper and white writing, in mirror image (reversed vertically). Anyone’s login does this (Windows 2000 network), and ordinary Word or Excel documents print fine. Again, other PC’s print to it fine as well. I’ve removed and re-added the printer, to no avail. And I’ve updated the driver to be sure it’s current. Any ideas?