The wording of the sign-up notification is weird. I've been meaning to post for a while, but it's a very minor point. It says:
"John Doe had just signed up 6 HOURS AGO".
"Had just signed up" is wrong.
I think it should simply say "John Doe signed up 6 HOURS AGO", or (less good), "John Doe has signed up 6 HOURS AGO".