I have a new canon. I have a new canon mp 620. It prints fine from my MAC but won't copy. The

Question

I have a new canon mp 620. It prints fine from my MAC but won't copy. The directions say press the HOME button the the color button twice. The printer sounds like it wants to pick up the paper, makes a bunch of clicks, then I get an error message that saysERRORRear Tray"there is no paperLoad paperand press OKAgain, it prinys fine from the MAC, there IS paper in the bottom tray, but won't copy.