Password Protection in Splendio Broken

I’m using the free Splendio theme by Design Disease for a pre-school’s website. They want a password-protected page but the password protection in Splendio is sending me to a WP admin login page. I turned off all plug-ins and that did not solve the problem. I switched the theme to Twenty Twelve and that solved the problem. I also tried Twenty Eleven and the password worked correctly there as well. I don’t know where to look to find the piece of code that is broken. I searched the functions.php file and did not find any password-related code, but I may have missed it. Splendio is not in the theme extension section of this forum, but it’s built on Twenty Ten if that is helpful. My knowledge of php is limited but I can follow instructions. Thanks for your help.