Kodak premium photo paper had the problem like yours. It was widely discussed on some forums about two years ago. But then looking at Kodak's instruction for the paper to be printed by Canon i960 it said to use plain paper setup and set Quality to high and halftoning to diffucsion. It did solve the problem for the Kodak paper. Your problems looks just like that. But I said it maybe a setup problem (like what's needed for Kodak paper). Give it a try it may surprise you (or not at all).