Thanks Callum. 

Yes I did activate it - and then spent about 15mins trying to find out how to remove it before posting here.    It keeps displaying at the top of the page (annoyingly) and I accidentally clicked on it instead of the link I was intending to click.  I've done a bulk edit and redefined my payment options and it seems to be OK now. 

Hi, thanks ... hopefully the bulk update fixed it.  Gah, wish it was a bit more intuitive.    I've just checked and bulk update has seemed to fix it! Thanks for your help.