Mine does it also, but it only takes a couple of cranks to sort.
The cooling fan always cuts in, and I assumed it was the water temp sensor on the top of the thermostat getting hot, hence the ECU cuts the engine like it had overheated. The other reason I thought this was the cause is because the first time it ever happend was just after I had refitted the thermostat, which I'd also just had a heat lamp on to set some araldite (which was used to stick the plastic pipe in the end.).
So, now I'm confused, because I would never have thought that an air temp sensor would have caused the cooling fan to run. Oh well, good to see we all get the same problem, what ever the cause is.