Printing problems:

1) Black and white text seems to be printing evenly, with no gaps or fading.
2) Black and white photos/graphics print with one vertical line (white) about 3-5/8 inches from right side of page (portrait orientation).
3) Color text prints with vertical bands of uneven color throughout page, plus dabs of yellow ink about 1 inch from the right side of the page, evenly spaced vertically about 1-3/4 inch apart, and beginning about 4-5/8 inches from top.
4) Color photos/graphics print with similar problems as text.

Is it the printer or the cartridges? This was a pricey printer new (over $600), with pricey consumables, and I'd much rather not give HP any more money!

Thoughts? Help? Thanks so much.