Access Denied: Displaying a Legal Notice When Users Log On

We need to display a legal notice when users log on to our computers. I entered the text of the notice in the Message text for users attempting to log on policy under the Default Domain Policy Group Policy Object's (GPO's) Computer ConfigurationWindows SettingsSecurity SettingsLocal PoliciesSecurity Options object. However, the notice isn't displaying when users log on. Why not?

Message text for users attempting to log on doesn't work unless you also define the Message title for users attempting to log on setting. Windows displays the notice (or the title) only when both settings are defined.