I saw that before and yes, it is clicked as you can see in the attached photo. I noticed it go away and come back as I clicked it and of course being labeled Options I was sure that was it. So after that I still don't see the Constrain Path Dragging. In fact mine doesn't look like yours. Mine has an additional choice of Auto Add/Delete which is checked. If I uncheck it nothing changes other than it being unchecked.
Im still stumped. This is a real copy of CS6 purchased. It is the Adobe Creative Suite 6 Design & Web Premium. Allows for 2 computers and so far I am the only one who has installed it.
TADA!!!! So I noticed the tool you were selected on when Constrain Path Dragging was in the options bar. I was on the pen tool so I figure that MUST be where that should be. Apparently I was wrong. I selected the black arrow and Viola! There is was.
Now to play. Thank you thank you thank you. I am sane again.