Many thanks for the help- schmunkee- the google was spot on, the second post mentioned the way you pause recording, then auto lap kicks in etc, this was the first time that I have run for a distance ie 3miles then stopped the timer, for 30 mins before restarting the timer at the start of a race, it was then during the race that the screen alerted me.
Anyway I think I know what the issue is, once again, many thanks.