Think I've sorted this out now (thanks everyone) What had happened was that someone had submitted a William Hudson born in Shepshed to LDS, when the parish records showed it was a John Hudson, so there was one William too many.
Thanks very much to all the brave souls who've helped me. I've now got back to William's grandfather & have been rattling around the Notts & Derbys records.
Should I now transfer this to "Completed" or keep it running in case (in case !!) I need help further back with the Hudsons ?