I rooted my Atrix before the 4.1.83 update with no problem, and then (for a variety of reasons) wanted to update and re-install the ginger blur rom. It would have taken me a very long time to do without this post. Thanks so much.
Hey, this whole experience of rooting is brand new to me, but I've already learned a LOT from these forums. Seems like a great community, and I'm glad to be a part of it.