Wordpress creates plugin tables locally, not in production

I am making a plugin for a client and i am trying to install it on their test server.

When i install the plugin locally, everything works fine. However, when i install it on their test server, the tables are not created. They don't have debug turned on, and i don't get any message that there was an error installing. I verify that the tables are not created, by using a plugin called database browser.

Here is the code, that creates the table, everything else is cut out. With this code the tables are created locally:

<?php
/*
Plugin Name: Integration Rating
*/

class IntegrationRating {

    const INTEGRATIONS_TABLE_NAME = "ir_integrations";
    const RATINGS_TABLE_NAME = "ir_ratings";

    /**
     * Called when the plugin is activated. Creates the tables for the plugin.
     */
    public static function activate_plugin() {

        global $wpdb;

        $sqlCreateTable1 = "CREATE TABLE IF NOT EXISTS `" . $wpdb->prefix . IntegrationRating::INTEGRATIONS_TABLE_NAME . "` (
            `post_id` bigint(40) unsigned NOT NULL,
            `rating` int(11) NOT NULL,
            `num_raters` int(11) NOT NULL,
            PRIMARY KEY (`post_id`),
            CONSTRAINT `post_id` FOREIGN KEY (`post_id`) REFERENCES `" . $wpdb->prefix . "posts` (`ID`) ON DELETE CASCADE ON UPDATE CASCADE
        ) ENGINE=InnoDB DEFAULT CHARSET=utf8;";

        $sqlCreateTable2 = "CREATE TABLE IF NOT EXISTS `" . $wpdb->prefix . IntegrationRating::RATINGS_TABLE_NAME . "` (
            `post_id` bigint(40) unsigned NOT NULL,
            `rater_email` varchar(255) NOT NULL DEFAULT '',
            `rating` int(1) NOT NULL,
            PRIMARY KEY (`post_id`,`rater_email`),
            CONSTRAINT `ratings_post_id` FOREIGN KEY (`post_id`) REFERENCES `" . $wpdb->prefix . IntegrationRating::INTEGRATIONS_TABLE_NAME . "` (`post_id`) ON DELETE CASCADE ON UPDATE CASCADE
        ) ENGINE=InnoDB DEFAULT CHARSET=utf8;";

        $wpdb->query($sqlCreateTable1);
        $wpdb->query($sqlCreateTable2);
    }

    /**
     * Called when the plugin is uninstalled. Removes the plugins tables from the database.
     */
    public static function uninstall_plugin() {

        global $wpdb;

        $sqlDropTable1 = 'DROP TABLE IF EXISTS ' . $wpdb->prefix . IntegrationRating::INTEGRATIONS_TABLE_NAME;
        $sqlDropTable2 = 'DROP TABLE IF EXISTS ' . $wpdb->prefix . IntegrationRating::RATINGS_TABLE_NAME;

        // Delete ratings first because of constraints
        $wpdb->query($sqlDropTable2);
        $wpdb->query($sqlDropTable1);
    }

}

function ir_activate_plugin() {
    IntegrationRating::activate_plugin();
}

function ir_uninstall_plugin() {
    IntegrationRating::uninstall_plugin();
}

register_activation_hook(__FILE__, 'ir_activate_plugin');
register_uninstall_hook(__FILE__, 'ir_uninstall_plugin');

new IntegrationRating();

I'm hoping someone has some clues to what could be wrong.

via Chebli Mohamed