Also having the exact same problem with a HP F2180 All in One, The only difference for me is that it was working fine for me in Gutsy, problems have only been occuring since I installed Hardy & then Intrepid (both fresh installs and not upgrades).
Also everything works fine printing over a network from my windows machine using samba (Printer connected to Ubuntu Machine), but doesn`t do anything over a ubuntu to ubuntu network
In Document Print Status Window the item being printed shows as processing for a couple of seconds and then changes to completed.
I Would also be grateful for any insights into how to solve the issue