My 2001 X5 turns but doesn't start. It does this

My 2001 X5 turns but doesn't start. It does this sporadically so it has been hard to diagnose. We have had some success - when faced with the problem - moving the lever to Neutral before turning the key. I have the impression the car refuses to start until something electronic from the transmission falls into place. Once it's going it is a great, powerful, smooth ride, no hesitations and no signs that something could be wrong. Thank you for any suggestions.