Ford Mustang: Starting Problem, rare occurence, starter solenoid

Question
I own a 1997 Mustang coupe automatic 98K miles.  Twice in the past month  when I turned the key to start the vehicle; the car powered up but the engine would not start. After repeated attempts to start the engine; I shifted to Neutral from Park while the car was powered up; and was able to start the vehicle in Neutral. I brought the car to the service dept of  a Ford dealership after the first occurence; and he said it passed all the diagnotic tests; the fuses; battery; starter; solenoid etc. were all fine.  I'm wondering if it may be a case where the gear doesn't fully engage in Park; since I'm able to start the engine in Neutral. Interlock problem ? Also over the past 2 years; very infrequently the same starting problem would occur; but on the second attempt the engine would start.   Any insights would be appreciated.

Thanks  

Answer
Sounds like a rare occurence.  I would take it back to Ford and tell them the part about being able to start it in neutral.  My immediate thoughts were fuse or starter, but if those checked out maybe it is some weird problem.  I am no help on this kind of thing, Sorry!