@MPMFV: Are you sure the ports in Boston and Florida are trade ports rather than fisheries or shipyards? A lack of trade ports would explain that message you get.
@Jaguar: I believe this problem has to do with a bug that is supposed to be fixed by a patch coming out next week. I don't know if you need a certain amount of trade ports to bring in goods from multiple nodes. Your problem could be a combination of these two things.