My previous posting explained the problem that an entire sheet has become 'macro assigned' since upgrading, despite even cutting and pasting to a new sheet.
I have since found that if I toggle down the sheet even one line, it cures the problem but doesn't eliminate it. I tried deleting the top line and also inserting another one but the damn problem persists.
Thank you for your acknowledgement Peter . Unfortunately I can't determine if a command has changed with the upgrade but it would seem to me to be tied up with the assignment function?