Inconsistant behaviour in Login screen.

[TitanKing]

When a user enters an incorrect username or password, the login screen shows the security animation and the text: "You used an invalid username or password. Remember, it is case sensitive.", after a few seconds it then correctly returns to the login screen.

However, when the user leaves either the username or password field blank, the message "You did not complete the username or password fields" is shown. But the user is not taken back to the login screen, instead the user is left with no further navigation options but is forced to click on the Log In | Out button in the menu.