If you check the website link I posted earlier it says on there that the spelling of the name has varied throughout the generations.
As you can see from Slowhands posts of the various Census for the Wiggles the name was usually written how the transcriber heard it. I don't think they bothered to check the spelling in those days!
As with all the research you need to check, double check, and re check until you're satisfied that the ancestors are really the ones you think they are.

Regards
Bertha