My 07 car flashes on an off sometimes too. When my girlfriend sits in the car sometimes its on and other times the light says "Passenger Airbag off", she weighs around 115-120lbs, is something wrong with mine?

 

afixer,
Now THAT"S funny!
Bob T.

 

Yes, its the Occupancy Clasification Sensor.
Read about it in the owners manual.
The RCM needs to be reloaded with the correct data to properly
classify whats actually on the passengers seat.
An actual passenger or just heavy cargo/groceries.
Seems she is not being properly protected some times.