HP 1220 working under GIMP?

[Bruce Burden]

   Hi All,

        Has anybody managed to get the HP 1220C printer to print at
   anything other than 150x150 dpi? If I try 300x300 dpi with a color
   image, all I get is black and white streaks... My HP1220 is connected
   to a HP JetDirect, if it matters any. Oh, yes, this is under GIMP
   1.1.25.

        Also, is anybody working on going beyond 300x300 dpi for this
   printer? It is capable of 1200x1200 dpi, after all...

                                                Thank you,
                                                Bruce