Maybe you'll get off the hook and it'll be something simple, like the prints coming from another drawer and it is set for portrait but the machine thinks it's supposed to be landscape.
Since you say that you've been told this, I'm assuming you haven't been there yet. I would first walk in, then have them do exactly what they've been doing to cause the jam. Rather than go through the machine, this approach will give you a quick idea of what they are seeing. You may be surprised at what's actually going on.
