I just went through this tutorial and created the touch controls he made for his game and they work great!
ISSUE: Controls break with Parallax at 0,0
I went ahead and added the controls to a UI layer with Parallax a 0,0 and for some reason the orb is acting very strange now. Is there something wrong with the calculations? Or is there something that I'm missing with regards to how this should function in a parallax layer?
[UPDATE]
No idea what the issue was, but I pulled the SANA controller from the TouchUI tutorial on Scirra and it worked like a charm.