My V6 ecu was drowned in October by a flooded plenum. The AA assured me that it was probably beyond saving, citing spidery internal shorts after drying out. However, I allowed it to dry very slowly using a dehumidifier, and all has been absolutely perfect ever since. I was given excellent advice from the forum, and Marinabrian very kindly offered to come and replace the ecu for me at very short notice, as the car would not start. Then it did, but I will certainly contact him if the problem recurs.
Apparently, the V6 ecu's are waterproof, but mine most certainly was not. It's great to know that people are there when you really need them! Many, many thanks to Marinabrian and Bororover, for offering me immediate help, even though the crisis unexpectedly resolved by itself!