Hi again Hilary, our resident guru! :)
As guessed, yes I am using the default value and from here grabbing the secondary data source and filtering the values for the fields PreferredName, Title and WorkEmail.
Funny you mention the form load rule, I did initially had one when I was using the people picker control, but changed it to text boxes/default values option in design so disabled it.
I'll give it a crack and see how I go...
Cheers