Our Epson Stylus Pro 9600 keeps giving us spotty test prints. All of the cartridges are full. We have run over 20 power cleanings. It will give a spotty print on one color, then seems to be getting better, but start giving spotty prints on other colors. We found this trick where you cover a paper towel in windex and let it sit over the cap assembly pad for twenty-four hours, but that didn't help. What could the problem be?