I am running AM on a Mac Pro with new Mavericks OS (10.9) and just saw something I have not seen before: I had a Southpole contraption open and clicked with my wireless Magic Mouse on one of the tabs -- say, Envelope 1 -- to make some adjustments. To my surprise, and without me understanding what I was seeing, the choice of tab suddenly switched and I was looking at an entirely different and unexpected set of controls -- LFO 1, for instance. I then realized that it was by scrolling up and down with my finger on the mouse's top surface, but only a wee bit, I was switching between these different tabs without meaning to. I have not seen this before, and I have been using AM with this same Mac and mouse for several years now. I doubt, somehow, that my finger's habits have suddenly changed; my guess is that something has changed in OS X's GUI-display code that is making this happen. Being able to switch tabs so quickly like this is not particularly helpful, to me at least, and it strikes me as a potential source of confusion.
But perhaps I am mistaken and Southpole has always behaved like this.