Genealogy / Need some help with Bublitz family origin. [23]

Ok, there seems to be some confusion with my family history that no one seems to know the answer to. Maybe someone here who knows about Polish history can help me straighten it out. I'm basing all of this on family stories, so there's no telling of the validity. My last name is Bublitz, the story goes that my Great Great Grandparents Frank and Mina came to the US from Bublitz Germany (now Poland) sometime in the later part of the 1800's. They settled in Chicago and had my Great Grandfather Erwin in 1896. At least that's always been the story. Now, I know that during WWI or II when Germany invaded Poland, they renamed some of the provences, Bublitz (I assume) being one of them. Bublitz is in Pomernland and is now Bobolice (Bublitz being the German spelling). It all sounds good, except for the fact that when my family came from Poland there would be no reason it would be called Bublitz. Bobolice maybe, but why the German spelling if it was before the war? This has been bothering me for years and no one seems to have the answers. If anyone can shed some light on this I would really apprecaite it.