Had a strange call today. Customer has a Cs500ci with the DP-760. They called because the machine continuosly had the message to clean slit glass. I got there and no message and glass was clean. Both the slit glass on the copyboard and the slit glass for the CIS. I went ahead and took the copyboard slit glass out and cleaned it. There have been instances lately where static has caused dust to collect on the bottom of the glass. That has caused lines on the copies. But This is a new one where the message popped up and the customer could not clear it. Thanks in advance for any help and pointers.