My 2003 1.8 TDCi starts fine each morning, but I have noticed a problem now. If I take the car on a short journey and turn it off before it has had time to warm up, when I try and start it again it fails to start and I could be sitting there for 10 mins trying to get it started. If the car is started and used for a long journey, I do not have this problem.

In summary:
If the car is started and stopped again before it gets up to temperature, it will be a pain in the arse to get going again. It is fine if stopped and started again when up to temperature.