Why are there different versions of the ordering of the Mishnayos and what is the "correct" version?

I have noticed some minor discrepencies in how the mishnayos in chapters of Pirkei Avos are numbered as well.

Now that we are starting the second time around with the first chapter, since Shavuos has now passed, I'd like to ask again the question I first asked more than a month ago.

Does anyone know why there are two different Mishnayos numbering and of the two, which version is correct?