This started recently. When printing a Word or Excel document using black only, I get small red and blue dots all over the page. But when I print using a color, there are no dots. The dots appear to be like ink was splattered on the page, but it's not really random. There's a definite pattern. I uninstalled and re-installed office. This is the same on my Windows PC and my wife's Mac, using the same printer. Any ideas?