Really? i didn't know about this. In my country, everyone puts up a nativity scene/manger and people don't mind.
In my opinion, I think people should stop over thinking things. All holidays have a certain "image" and there is nothing wrong with that. In fact, the reason why we have Christmas is because it's the birth of Jesus, thus the Nativity scene.
Also, just a thought, but the people making a big deal out of this, are they really for "political correctness" or just trying to create an issue?