post scheduler doesn't work

Hi there

first, let me say thank you for your amazing plugin.
unfortunately, after installing ‘better wp security’ I realized that i can’t schedule my posts anymore 🙁
when i set a date, publish button doesn’t change to schedule.
i install bwps on my two sites, and all of them encounter with this problem.
is anyone else has this problem? please help!

http://wordpress.org/extend/plugins/better-wp-security/