It is possibly being caused by the fuel injectors leaking fuel when the car is not running, flooding the engine. try pressing the accelerator all the way to the floor before and during cranking the motor.This will cause the engine management system to prevent more fuel being introduced into the motor. The motor will start much more readily if this is the problem...(I am assuming this is a fuel injected motor, but the principle still applies to carburetted vehicles).
pomandrew
April 2009