Is there a known problem with new shape Nissan MIcras?

We've had our Micra 1.5dci for just over 3 years (ie warranty just expired!), and we've just been told that the Fuel injectors are worn and corroded! I'm not a mechanic or any kind of expert, and so don't know if this is right, but it seems to be slightly unbelievable given the age of the car, and the fact that it has been regularly serviced for the first 3 years. Is this possible? Or is there some sort of known issue with this. I've been scanning the groups, and there does seem to be a common thread.