Hi All,
Thanks for the posts here. I've been following it hoping for duplex printing on my HP6122 since the thread started. I had it working in 10.5 using the HPIJS drivers. I tried updating them for 10.6 and while they print fine the duplex feature no longer works.
It almost seems that the problem is in the way the OS itself handles printer communication since both the new Gutenprint and HPIJS drivers have the OPTION for 2-sided printing, but the printer just takes in another sheet and prints 2 separate pages no matter what I try.
My HP6122 with duplexer is connected to my Airport Extreme for wireless printing, and again used to do duplex printing with Leopard.
For everyone's reference here is the link to the HPIJS drivers I've been using and testing:
http://www.linuxfoundation.org/en/OpenPrinting/MacOSX/hpijs
Good luck and I hope to get duplex printing back soon!
--Geoff