A.
It is not a printing error. The 51st Edition had PG III assigned to UN 1845 but from 1 Jan 2011 (52nd Edition) there will be no PG for Dry Ice.

Furthermore, shipment of dry ice itself or as refrigerant for other DG is not permitted when shipping as Excepted Quantities. When shipping as LTD QTY, Dry Ice is not permitted ?gas is?h but per DGR 5.0.3.2 (c), Dry Ice is permitted as refrigerant for other dangerous goods. In addition, when dry ice is used as refrigerant for non-dangerous goods, a DGD is not required but an entry must be made on the AWB. Per DGR 8.2.3, effective 1 Jan 2011, it will be no longer necessary to indicate Class 9.