It's not a bad thing (the sub's digital amp is pretty efficient), but it can probably be avoided. If you've having trouble with the auto turn-on, you might consider turning down the volume knob on the sub's amp and then increase the subwoofer trim on your receiver to get back into calibration. This will increase the volume of the signal being sent to the sub, allowing the auto-sensing to work more reliably and without any intervention on your part.