Shuts off while driving, restarts after cooldown

[krank]

It's now twice my Focus 2000 has shut down while driving on local streets, and I've been fortunate that no accidents happened and the car wasn't blocking traffic after. When it works it's fine (low mileage, under 50K) and it will work just fine after a cooldown. Right after a stop the starter turns, but the engine won't catch. The car was warmed up when it happened, but not hot, and there were no advance warnings. It must be electrical, maybe some safeguard like the fuel line cutoff, but would that reset when the engine cools? Is there a solenoid or sensor which is supposed to prevent the engine from starting, but is now shutting it down? I'd appreciate any suggestions, as I'm afraid to drive locally, let alone risk a stall on a parkway.

[Sponsor]