I found lots of sites that have information talking about setting AllowOverride AuthConfig. However, my Apache2 on Ubuntu was not doing any password protecting for me. I figured out that the problem was that I needed to edit the /etc/apache2/sites-enables/000-default file to change this setting. After I changed this file, it all started working for me. Not sure why I needed to change this file in addition to the apache2.conf file, but it solved my problem. Hopefully it will solve yours.