Has anyone had any issues with Red, Yellow, or Green lines appearing on their scans? These lines aren't always in the same spot, and I don't believe it to be anything physical (glass, background, etc) but even still, I have replaced the glass, background, calibration pattern. I've had this issue on 4 different 4500 scanners, but never a 4200 or an 815.

These lines will appear, then disappear for months before popping up again. Turning the machine off, then calibrating will get rid of them for sometimes an hour, sometimes a week.

Anyone else seen this?