has_cap is deprecated since wp 2.0

You have to update the function of your plugin like this:

// Displays WordPress Blog Facebook Members Options menu
function as_facebook_mem_add_option_page()
{
if (function_exists(‘add_options_page’)) {
add_options_page(‘Facebook Members’, ‘Facebook Members’, ‘Administrator’, __FILE__, ‘as_facebook_mem_options_page’);
}
}

In the last, the #3 argument in function add_options_page can’t be a number, but is string identifying Roles and Capabilities for the users.