Hello, I see this thread is dead since January.
I just want to note here, that I changed all Pololu current sensors to Amploc 25 (linear to +-60A) recently. They are virtually undestructible by accidental short circuit in the sensed section (The Pololu usually dies, when the short circuit current exceeds 100A). Also the jitter seems to be ok even when the sensor Vcc is connected to +5V Arduino pin, because connecting anything to the Vref pin, as I suggested above, is not recommended.