I turned off the tap-to-click and since then have had no
more problems with the jumping cursor.

The static suggestion is very interesting so I have appointed a teaspoon to
become a lucky talisman to be touched before Ithe computer. A jug of water now
stands close by.. I am usually barefoot in the house but æos of windows nude
could be too horrible a sight for passers by/postman so cotton tshirts will be
order of the day. I will let you know how I get on with future emails to the
said contact.

Two questions -

1- why do extra addresses happen with only the most recent contact and no other?
2- the chair is microfibre. Is that likely to create excess static?