first of all, this a fairly old topic, please try not to bring up old topics. onto business...
you see the three header pins where you are supposed to plug your servos in?
the two outside pins are something called a power bus, because they are servos they get unregulated power.
your sensors normally need regulated power to give good reasons, hence regulated and unregulated buses.
from the chip outwards it goes, signal, +power, ground.
so the sensor and servo power buses are two different things, one gets it from the battery directly, the other gets it from the regulator which provides it with +5v regulated. hope that explained things better...