I'm back on this thread, because our stop'n'start warning lights have come back on again! but read on...
As you may have notice from another thread of mine, our little car has been involved in an accident, where a big truck knocked it into a spin, and half the air bags popped out. This makes us grateful that we considered safety when we bought the car, as looking at some other cars we looked at in the same price and size range, we can see that there would have been potentially serious injuries in those cars in the same incident. We're particularly grateful for those side air-bags.
Unfortunately, this meant our car was in the shop for a while, and as part of the repairs, it seems that the on-board computers needed resetting to factory defaults, it seems.
As the solution to our warning lights issue was to apply a software update, it seems that the garage who did the factory reset (a Fiat dealer), didn't check which updates were already applied, and just left it with the software which it had when it had the warning lights problem.
Dissapointing, but at least we think we know it can be fixed quite easily. Now we just have to re-convince our dealer that we know what the fix is for it...