Hi Roy,
Thats a very good question! I have almost no knowledge of rotary engines so don't know the answer, but would hazzard a guess, based on experience alone, that lots of engines that stall when cold can be a problem to restart due to poor combustion/fueling at less than optimum temperatures. The reason I stated valve lifters as a likely cause is because of the loss of compression. A lot of people think the cambelt has broken when this happens.
Regards,
Bryan.