logged-in users shouldn't nedd a post password

Hey guys,
some of my posts are password protected – for those how don’t have an account for my site.
Logged in users shouldn’t need to type in an extra password for those posts. So I tried to put some code (using add_filter) in my function.php to change the post_password_required function to take care of is_user_logged_in():

function check_post_password_required() {

	if (is_user_logged_in()) return false;

}
add_filter('post_password_required', 'check_post_password_required');

But that doesn’t work. What am I ding wrong here?
Maybe post_password_protection is wrong in this case? Do I better have to add a filter/action or the get_the_content function?

Regads,
miboe.