"I tried this printer on Ubuntu
8.04 Hardy Heron, and with the help of hlplip, it works fine. I had to
do a little extra work, because the standard Ubuntu 8.04 had hplit
2.8.2 on board, which is not appropiate. You should install 2.8.5 or
higher.
I tried the automatic installer, but that did not work. Then I
installed 2.8.7 manually, followed the instructions, and everything
works fine!"
gNS 2.2 is based on Ubuntu 8.04, which means that hpilp is going to be 2.8.2.
You will need to install a later version of hpilp. Someone could set up packages or a PPA maybe? I'd love to see a gNS PPA/backport repository. We have one for icecat :)
PLEASE NOTE: hpilp does include binary-only firmware for certain printers. The d2560 does *NOT* require binary firmware--BUT if you use a vanilla hpilp install you will probably end up with this firmware lying around on your disk, being useless and taking up space and looking blobby.
A PPA/package repo for hpilp would fix this, because we'd just strip out the firmware.