Discovery SE7 II start and stall

Hello
I have a 2003 Discovery SE7 with 74k mi.  up to date with all services. This weekend (on the way to a wedding) I tried starting the car and it cranked but no fire. the crank sounded strong.  I came back later that night and popped the hood and manipulated the battery cables and it started right up.  Sunday, I drove to a meeting (no Problems).  On the return trip while approaching a stop it died and soon after the  service engine light illuminated.  I pulled over, popped the hood and manipulated the cables.  Cranked but no fire.  I locked the car and then unlocked again thinking maybe the alarm trigger or something?  Car fired right up with no service lights and I drove home.  Subsequently it happened again.  I locked and unlocked the truck and it started. 

Have any of you heard of this issue?  Thanks. 

In the 2 years I have had my 2003 Disco II, this has happened to my wife 2 or 3 times.  It never happened to me so I figured it was user error 

Each time she used the key fob to lock the doors (thus setting the alarm), and then unlocking them.  Each time she has done this the truck fires right back up.  I just asked her and she said she never had the engine light come on during this, nor has ours ever died while actually driving down the road.

I just figured it was a quirk with the alarm starter interrupt relay, and perhaps the relay didn''t fire when the doors were unlocked as it should.  I have never investigated further or attempted to replace the relay because it only happened a couple of times and hasn''t happened since. 

If yours died while driving, there may be something else going on, as that would disprove my above theoy.

the locking/alarm has nothing to do with a cranking no start, your active anti-theft, alarm, will cause a no crank situation. could be the early stages of a faulty crank sensor

Thanks.  I was curious also of the fuel pump.  Could a crank sensor stall the engine while running?  

Funny.  My wife was the last to use the truck before the issues!

definitly, the crank sensor is what is used to determin when spark should occur, if it fails, or sends incorrect signals, then ignition will not happen, or happen at the wrong time, and kill the engine. as to the fuel pump, it would probably be a more consistant problem, however, i could see the fuel pump relay causing something like this

Crank sensor.....final answer

Hi Guys.  Thanks for your collective input.  LR tech- You are correct sir!  Crank sensor it was and we are back enjoying the LRD.  Thanks again guys!