Thanks - module is now in place and working fine.
Yes, I know about the CB Auto Actions / System Actions button under CB Auto Actions... I have tried off and on but can't figure out who it is that makes me see if a user has written something to me... But I have managed to make the notification work if I respond to the user with a like or comment... I have been reading and trying but not managed to make it work - thought you might know which one it was..?