I'm pretty certain I am having the same problem as your brother.
When I take the car in for service, I'll have Pontiac look at it. I'll know which direction to point them in and I won't go for the new key either. When I purchased the car, I needed a new chip regarding the engine safety cut off. It involved the security system so I can see this new occurance as a related issue.
Thank you for your input and tips.
