当SQL语法正确时，Wordpress dbDelta函数不添加表

Hi I've written a function to add a table. I've tested my syntax and it works in my phpmyadmin but for some reason it's not being activated in my plugin? :S

class clients{
    public static $version="1.0";
    protected static function setup_tables(){
        global$wpdb;
        require_once(ABSPATH."/wp-admin/includes/upgrades.php");
        dbDelta("CREATE TABLE ".$wpdb->prefix."hippie_clients (ID mediumint(9) NOT NULL AUTO_INCREMENT, email varchar(100) NOT NULL, password varchar(512), paid tinyint(1) NOT NULL DEFAULT 0, firstname varchar(50) NOT NULL, lastname varchar(70) NOT NULL,signup TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP, free tinyint(1) DEFAULT 1,gender tinyint(1) NOT NULL, lastlog varchar(200), UNIQUE(email), PRIMARY KEY(ID))$wpdb->get_charset_collate();");
        if(!isset($wpdb->clients))$wpdb->clients=$wpdb->prefix."hippie_clients";
        add_option('Hippie_clients_version',self::$version);
    }
    //I'm using another class to manage my activation hooks etc but this is the basic idea
    public static function setup(){
        self::setup_tables();
    }
    public function run(){
        register_activation_hook(__FILE__,(array('clients','setup'));
    }
}
$clients=new clients();
$clients->run();

But the table isn't being added. Is my table syntax? Or the way I've set it up? Is it the protected keyword?

There were a few reasons I was getting an error. Firstly register_activation_hooks() is a tricky issue I had. It was not registering using my class structure (not shown above).

To solve this I made a quick fix by registering the activation in my plugin's main file.

The second was there needs to be a space between UNIQUE and bracket and 2 spaces required between PRIMARY KEY and bracket.

I also found that $wpdb->get_charset_collate() was causing an error with my table creation so simply removed it for now.