The 2.2.1 drivers still do not fix the issue with the top and bottom page margins on DesktJet printers. Even with these drivers, top and bottom margins are anywhere from 1/4 to 2/3 of an inch off. There are also many lacking features, stability problems, and, when I tested the 2.2.1 drivers with my DeskJet 940c, I found the print spooling, queuing, and transfer to printer speeds to be unacceptably slow, with waits of 15-45 seconds between sending the print command and the printer actually printing single page plain text documents.
I have returned to using the open-source CUPS hpijs drivers, available at http://www.linuxprinting.org/macosx/hpijs/
The hpijs drivers offer better support of printer features, and more consistent print output in regards to margins and other settings. Spooling and transfer performance is also great. The hpijs drivers are very similar to GIMP-print, but I find that the hpijs drivers have a better presentation in the print dialog, and support the features of HP DesktJet printers more fully than GIMP-print.