to make my printer (hp4000) work on gutsy i had to boot an old ubuntu live cd 6.10 and test it there (add new printer )

with the folowing config Manufacturer Hp, Model 4000, Driver hpijs , Connection Part Port #1 (Epson)
the last line seems to be very important

Then i deleted my /etc/cups from gutsy and copied all the /etc/cups directory from 6.10

I will see later what is the difference between the two configs