Front passenger airbag

Bought 09 Buick Lacrosse CX 4/11 with 26K mi. Jun. '12 passenger airbag began turning off intermittently with passenger in seat. Buick shop replaced pps module. In 2/13 it began doing it again. This time buick shop said the computer was being confused by placing items on the seat weighing less than 75-80 lbs. and didn’t know whether to stay on or turn off. They “reset” computer. Been placing items on the seat ever since buying and never experienced this problem. Is the airbag sensor that sensitive? It’s doing it again, a few days after the shop “fixed” it with the reset, and I only placed a newspaper on the edge of the seat and snatched it back up immediately.

Sounds like a bad sensor(s) in the passenger seat…