It's all related to the sudden non-existence of these elements all us addon coders have taken for granted for so long. You'll need to position the button manually with SetPoint when you Show it. Any of us who have ever written addons that add elements in relation to elements of the new Blizzard addons will have to be reworked to watch for when those addons load.
Thanks for pointing that out, Isharra. I don't know if he just added that comment on his forum or I missed it, so I apologize if it's my error and if I (almost) started something by my post. I looked at the code for credit and didn't find any, but as long as he's acknowledging that he based it on Neriak's, then I think that's cool. I have nothing against borrowing from addons as long as proper attribution is given. The shared nature of addon code has always been a good thing, in my opinion.