Plugin can't create table

Good evening.
I am newbie @ wordpress plugin programming.
Briefly..
In my index plugin file i am requiring once for functions file in which i have writen IF function for “if installation file (setup.php) exists -> include setup.php and register_activation_hook for table installation function”.
Here is setup.php code:

//	Setting up table version for later upgrades
	global $sarsauto_version;
	$sarsauto_table_version	=	"0.1.";

	//	Creating table
	function sarsauto_table_setup() {
		global $wpdb;
		global $sarsauto_table_version;

		$table_name = $wpdb->prefix . "sarsauto";

		if( $wpdb->get_var( "show tables like '$table_name'" ) != $table_name ){
			$sql = "CREATE TABLE " . $table_name . " (
					id int(11) NOT NULL AUTO_INCREMENT,
					UNIQUE KEY id (id)
					);";
		}

		//	The dbDelta function examines the current table structure,
		//	compares it to the desired table structure, and either adds
		//	or modifies the table as necessary.
		require_once( ABSPATH . "wp-admin/includes/upgrade.php" );
		dbDelta( $sql );

		add_option( "sarsauto_table_version", $sarsauto_table_version );
	}

And here is IF function of functions.php:

//	Asking for setup.php file and if exists create function
	if( file_exists( dINCLUDES . "setup.php" ) ){
		//	Require setup.php file
		include( dINCLUDES . "setup.php" );
		//	On plugin activation ask for table setup function
		register_activation_hook( __FILE__, "sarsauto_table_setup" );
	}else{
		echo "Error: file doesn't exists!";
	}

THE PROBLEM is whenever i am refreshing my database’s list of tables, no new table is added (in this case ‘sarsauto’ table).
I have done everything like in wordpress plugin creation documentation.
Please help. This issue is making me crazy.
Thanks in advance,
Ricards