Safety interlock switch-Altima 1998GLE

[MikeArizona]

Greeting...I'm a new member and have just bought a 1998 Altima GLE for my daughter to get to work. The car runs fine most of the time but on occasion won't start. Battery and cables are fine. I took it to my ASE guy who told me the safety interlocking switch for security was blocking the starter motor from turning over. He said just put the ignition key in the door lock; lock it and unlock it when the car won't start. I did that and nothing happens. Suggests? Has this happened to anyone else?