Analog_M0n:
I see, is there a way to reduce the current supplied to the Arduino?
Dunno. Someone with higher hw-fu must step in at this point. I suspect you must supply Arduino with as much current as it needs, otherwise there will be problems. If the Arduino draws too much current the solution is not to give it less, but to understand why and see if it's possible to reduce consumption.
What puzzles me, though, is why it seems the board is consuming more current when running on 9V than when running off of usb power... ?-|