A couple of years ago I purchased a new MacBook Pro and was given a free C4780 as a bonus. Recently I tried for the first time to print some photos using photo paper. The paper gets hung up at one corner and jams. It does it with both 4x6 and 8x10 paper. The jam occurs as the paper re-enters the printer from the back during the transport. I've searched for information about the maximum thickness of paper that the printer can accept, but have had no luck. The paper I am using is 69 lb., 255 g/m2, 10.4 mil. I'm not sure which of those figures is most important in this situation.
Any insight as to why this problem is happening would be greatly appreciated.