I had this problem with my old Canon. It would do one good print then I'd have to clean it in between prints so it was eating up the ink. Is it compatible with your operating system Chris? Mine worked fine for months when I bought my new laptop (Vista) then all of a sudden, banding. I had to buy a new printer compatible with Vista (sorry) and put the old Canon one in the room with the desktop using XP.
Hope you get it sorted
hugs
Jan
x