Thank you. The document feeder does not appear to be the problem here. We have started having our users select the specific tray on the display that has the correct paper size. Keeping the tray selected manually instead of automatically seems to help. I wonder if we don't have a motherboard issue here.
Assuming you are using the document feeder for making copies, make sure that the document feeder guides are tight around the paper. They can move especially with a big stack.
I have a WC7545 that occasionally has a problem with paper sizes used to complete copy and print jobs. For example.... sometimes it will start an 8.5x11 copy job, produce a few normally, and midway through the job will mysteriously start pulling bigger paper from a different tray. Help please??