Just put my G0555 together. Can anyone who owns one tell me if theirs vibrates? Mine visibly vibrates pretty badly when I start it up and when I turn if off. When it is running there is some very noticable vibration as well, but not as bad as when I first turn it on or when I turn it off. There seems to be a harmonic that it is hitting durring the ramp-up/ramp-down time. Is this normal?