2001 Intrigue, a strange security problem

Security light comes on every once in awhile. Also, every once in awhile it won't start, wait a little while and then it will start.

The weird thing is, this car doesn't have a resistor on the key that I can tell. We even cut a generic, plain metal key and the car starts with that key, no security light or anything.

What am I missing?

Thanks for any info.

Intrigues have the Passlock VATS system, therefore no resistor pellet. GM Passkey I/II have the resistor pellet on the key. Then Passkey III got rid of the pellet.

Maybe a worn out key?