02 cav 2.2 sohc auto im working on has an intermittent problem...

it came to me running fine and was told the vehicle wouldnt start intermittently... after making 20 sucessful starts i decided to take it for a ten mile trip... nothing out of the ordinary. shut the car off, started it fine twice more. took it for another drive and the theft and service light (the one with the wrench next to the theft light not the check engine light) came on... shut the car off started it fine once more. shut it off again and NOW the car will not start. it cranks over just fine but the theft light will blink and the service light is on.... as im typing this i have the key forward for the 15-30 minute theft bypass time to hope it starts... if it does start then that would indicate an ignition tumbler issue correct? if it doesnt what else could it be?

so the car started..... after two trys whats the deal?