No user pins showing in GMap

After extensive searching I can find nothing about why my GMap is not showing any pins. I'm using D6.x and the GMap and Location modules. I had expected that once set up the map would reference address/location data in my user accounts and plot points showing the global spread of users, but after much work trying to figure this out I cannot get pins to show.

Does anyone have any experience with this module that can shed any light on this?

Thanks in advance