@jamesstar - if you downloaded Master on 26th August, then download it again as there was a bug in the version available on that date. More specifically, I believe the fix is in fuel\modules\fuel\models\fuel_users_model.php (although there are also …
Not sure what's happened there then - I downloaded FuelCMS from Master 9 minutes after that commit (entirely by coincidence, not by design - this is my first try of FuelCMS).
I'll re-download and let you know what happens.