Yes, printing does work properly from other apps. (CD-covers are a little too small, but...)
I did find a workaround, I lie and call my printer an HP Desk jet 840C. Then the printer
works fine, must reduce the ink volume a little for perfect pictures.
Gimp has a seperate setting for printing. If you check the setup under printing, you will find that there are some added control codes to the print command. I found that I had to change these settings according to the instructions on http://hpinkjet.sourceforge.net/ for the hpijs driver.
It is documented someplace on what needs to be changed.
-- Robin Laing