Shift Gear Lock Cause of Car Not Starting?

I have a 1996 Mazda 626 LX with V6 engine and automatic transmission with 69,000 original miles that I put on it. I have taken excellent care of this car - oil changes every 3,000 miles, transmision flushed, etc. For several months, I have been having problems starting the car. No codes showed up at my mechanic's shop. I also know to check to be sure that car is securely in Park. I remembered reading about the gear shift lock when I first purchased the car. Pulled out the manual, tried with one key, no go. Put extra key in shift lock as I turned ignition key, and voila, it started. This has worked on the second try(first try just regular starter) until yesterday. I went through same routine with shift lock, but it would not start. After about four tries and a few prayers, it started. Is this truly the problem, or just a fluke that it has worked? If it is the problem, what is a long term fix? I'm a little ole lady from Pasedena(actually, Visalia) on a very limited income! Cannot afford another car. Besides, I love this one! I am very concerned about getting stranded on a desolate road or actually anywhere. I think twice before turning off the ignition. :-( Thank you for any help you can give me. I made a small donation. :-)