My Canon Pixma iP3000 has suddenly stopped printing exactly half of the column of black pixels. That is, I get about 6.5 mm of the total width of 13 mm that it should print in one sweep. This is so clear cut (and happened from one print to the next) that I don't believe it is an issue of blocked jets. Anyway, I've done many cycles of jet cleaning, taken the print head off and cleaned it with alcohol, all to no avail. It is as if control to the jets on half of the black print head has been turned off. I wonder if anyone else has ever seen a symptom like this. Thanks Gib