I clean the glass of my scanner when I start noticing dots show up in the scans where I know there should not be such a character. And almost always, I find a tiny circle of something stuck to the glass, about the size of the head of a pin. Otherwise I don't clean mine. So maybe once a month or once every three weeks. I probably don't use my scanner as heavily as others do, though. Jamie in Michigan Currently Reading - Guarding the Secrets: Palestinian Terrorism and a Father?s Murder of His Too-American Daughter - Ellen Harris