After a year and a half of automatic duplex printing, I suddenly lost the option to print duplex and a popup keeps coming up, whether I'm printing or not, that tells me how to flip the pages for manual duplex. I reinstalled the drivers and it did not help either the printing or the popups. I went into the printer properties/device settings and clicked "allow duplex" and unclicked "allow manual". It hasn't restored duplex printing but at least it now prints all the pages and not half of them and the annoying popup has gone away. How do I get duplex printing back? Is it just gone? It's a Laserjet P1606dn and my operating system is 7.0. Happens on both my laptops. Thanks for any help.