This problem has been discussed before in this forum as well as more widely on the Internet. The Pro-100 reports a paper jam when there is none, especially with 4x6 prints and often when using Canon Photo Paper Pro Platinum. Other paper sizes may print without this problem. Sometimes, but not always the "paper jam" problem is temporarily solved by doing the roller cleaning in the maintenance portion of the print settings dialog. I had that experience a couple of years ago and was able to print but the issue returned when I recently attempted to print again this week after a long period of no 4x6 photo printing. After tussling with it for a couple of hours, including roller cleaning, I made a very interesting discovery.
The fake paper jam is specific, in my case at least, to the Pro Platinum paper. I can print normally every time with Ilford Galerie Smooth Pearl 4x6 paper and fail ever time with Pro Platinum. It's hard to explain -- there is no obvious difference in the thickness of the two papers but the Ilford might be a bit more flexible. There must be another factor involving the printer itself, as in the past I and many others have often printed 4x6 photos with the Pro-100.
