The middle and the back should change too but that all depends on how you have it plugged into the breadboard. I think you want the longest dimension of the POT parallel to the longest dimension of the breadboard and the pot on the divided side if you have the standard breadboard.
Here is a breadboard pic.
http://wiring.org.co/learning/tutorials/breadboard/ Note the break in the parallel busses. A lot of people think that there are 4 bussed parallel to the longest dimension. Note that there are eight busses.
Let's ask what are your resistor values? Something about 220-270 and what else?
The regulator sometimes needs a minimum load to work, otherwise it tends to stick close to Vin.