Delete user from ReadyNAS Remote?

I have one user on ReadyNAS Remote which has remained my main account for accessing my NAS (NV+ v2)...

I can create a new user and then delete that user - without any problems! I cannot however seem to delete my 'main' user account? I can hit delete, though continue to log back in as 'me'? When I hit delete, should that one remaining account also delete?

Any thoughts would be appreciated...