Ok, you appear to have the pot and the 3.3k resistor connected in parallel, and not in series. That would explain why you see the same readings, and is borne out by the math; (3300*1000)/(3300+1000) = 767.

I think that you've probably connected the non-regulator end of the 3k3 resistor to Ground, ie, to the wrong end of the pot.