Do any of you experience problems w/ the passenger airbag light not going on for lighter people? I'm 140lbs, and my wife, 100lbs, when she sits there, the light often stays on the "off" mode. I don't know what the threshold is for weight that will activate the sensor, but it seems to be set rather high. When I sit there, it seems to always be on the "on" position. Is this sensor sensitivity normal or should I bring it in to have it serviced on? Thanks!