Once you have switched of do you recharge the battery?If answer is no,then I'd be looking at the cylinder head gasket.Sounds like you have coolant leaking into the cylinder/s.Remove all spark plugs and spin the starter for 10 sec's or so,then refit plugs and retry,If it starts then problem confinrmed.A certain ammount of fluid will be seen to exit the plug hloes when spinning over would confirm hydralic lock.
caine, August 2008