ayuda con script de mysql

[qsflay]

tengo el siguiente script:

Código:

SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0;
SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0;
SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='TRADITIONAL';

CREATE SCHEMA IF NOT EXISTS `projecte` DEFAULT CHARACTER SET latin1 COLLATE latin1_swedish_ci ;

USE `projecte`;

CREATE  TABLE IF NOT EXISTS `projecte`.`usuari` (
  `id_usuari` INT(11) NOT NULL AUTO_INCREMENT ,
  `nom` VARCHAR(45) NULL DEFAULT NULL ,
  `cognom` VARCHAR(75) NULL DEFAULT NULL ,
  `login` VARCHAR(45) NULL DEFAULT NULL ,
  `passw` VARCHAR(80) NULL DEFAULT NULL ,
  `mail` VARCHAR(45) NULL DEFAULT NULL ,
  `tipus` VARCHAR(1) NOT NULL ,
  PRIMARY KEY (`id_usuari`) )
ENGINE = InnoDB
DEFAULT CHARACTER SET = utf8
COLLATE = utf8_spanish2_ci
COMMENT = 'tipos S= SuperAdmin i A=Admin';

CREATE  TABLE IF NOT EXISTS `projecte`.`pagina` (
  `id_pagina` INT(11) NOT NULL AUTO_INCREMENT ,
  `nom_p` VARCHAR(15) NOT NULL ,
  `ordre1` INT(11) NULL DEFAULT NULL ,
  `ordre2` INT(11) NULL DEFAULT NULL ,
  `ordre3` INT(11) NULL DEFAULT NULL ,
  `ordre4` INT(11) NULL DEFAULT NULL ,
  `ordre5` INT(11) NULL DEFAULT NULL ,
  `id_propietari` INT(11) NOT NULL ,
  `id_modifica` INT(11) NOT NULL ,
  `id_subpagina` INT(11) NOT NULL ,
  PRIMARY KEY (`id_pagina`) ,
  INDEX `id_propietari` (`id_propietari` ASC) ,
  INDEX `id_subpagina` (`id_subpagina` ASC) ,
  INDEX `id_modifica` (`id_modifica` ASC) ,
  CONSTRAINT `id_propietari`
    FOREIGN KEY (`id_propietari` )
    REFERENCES `projecte`.`usuari` (`id_usuari` )
    ON DELETE CASCADE
    ON UPDATE CASCADE,
  CONSTRAINT `id_subpagina`
    FOREIGN KEY (`id_subpagina` )
    REFERENCES `projecte`.`pagina` (`id_pagina` )
    ON DELETE CASCADE
    ON UPDATE CASCADE,
  CONSTRAINT `id_modifica`
    FOREIGN KEY (`id_modifica` )
    REFERENCES `projecte`.`usuari` (`id_usuari` )
    ON DELETE SET NULL
    ON UPDATE CASCADE)
ENGINE = InnoDB
DEFAULT CHARACTER SET = utf8
COLLATE = utf8_spanish2_ci;

CREATE  TABLE IF NOT EXISTS `projecte`.`element` (
  `id_element` INT(11) NOT NULL AUTO_INCREMENT ,
  `nom` VARCHAR(25) NULL DEFAULT NULL ,
  `resum` TEXT NULL DEFAULT NULL ,
  `id_pag` INT(11) NOT NULL ,
  `id_modifica` INT(11) NULL DEFAULT NULL ,
  `id_tipus` INT(11) NOT NULL COMMENT 'pot ser 1, 2, 3 o 4' ,
  `codi_video` TEXT NULL DEFAULT NULL ,
  `ruta_arxiu` TEXT NULL DEFAULT NULL ,
  INDEX `id_pag` (`id_pag` ASC) ,
  INDEX `id_modifica` (`id_modifica` ASC) ,
  PRIMARY KEY (`id_element`) ,
  CONSTRAINT `id_pag`
    FOREIGN KEY (`id_pag` )
    REFERENCES `projecte`.`pagina` (`id_pagina` )
    ON DELETE CASCADE
    ON UPDATE CASCADE,
  CONSTRAINT `id_modifica`
    FOREIGN KEY (`id_modifica` )
    REFERENCES `projecte`.`usuari` (`id_usuari` )
    ON DELETE SET NULL
    ON UPDATE CASCADE)
ENGINE = InnoDB
DEFAULT CHARACTER SET = utf8
COLLATE = utf8_spanish2_ci;

CREATE  TABLE IF NOT EXISTS `projecte`.`imatge` (
  `id_imatge` INT(11) NOT NULL AUTO_INCREMENT ,
  `nom` VARCHAR(25) NULL DEFAULT NULL ,
  `ruta` TEXT NULL DEFAULT NULL ,
  `descripcio` VARCHAR(45) NULL DEFAULT NULL ,
  `id_tipus` INT(11) NOT NULL ,
  `id_modifica` INT(11) NULL DEFAULT NULL ,
  `id_pertany` INT(11) NOT NULL ,
  PRIMARY KEY (`id_imatge`) ,
  INDEX `id_modifica` (`id_modifica` ASC) ,
  INDEX `id_pertany` (`id_pertany` ASC) ,
  INDEX `id_tipus` (`id_tipus` ASC) ,
  CONSTRAINT `id_modifica`
    FOREIGN KEY (`id_modifica` )
    REFERENCES `projecte`.`usuari` (`id_usuari` )
    ON DELETE SET NULL
    ON UPDATE CASCADE,
  CONSTRAINT `id_pertany`
    FOREIGN KEY (`id_pertany` )
    REFERENCES `projecte`.`element` (`id_element` )
    ON DELETE CASCADE
    ON UPDATE CASCADE,
  CONSTRAINT `id_tipus`
    FOREIGN KEY (`id_tipus` )
    REFERENCES `projecte`.`element` (`id_tipus` )
    ON DELETE CASCADE
    ON UPDATE CASCADE)
ENGINE = InnoDB
DEFAULT CHARACTER SET = utf8
COLLATE = utf8_spanish2_ci;

CREATE  TABLE IF NOT EXISTS `projecte`.`error` (
  `id_error` INT(11) NOT NULL ,
  `misatge` TEXT NULL DEFAULT NULL ,
  `contador` INT(11) NULL DEFAULT NULL ,
  PRIMARY KEY (`id_error`) )
ENGINE = InnoDB
DEFAULT CHARACTER SET = utf8
COLLATE = utf8_spanish2_ci;

SET SQL_MODE=@OLD_SQL_MODE;
SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS;
SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS;

al ejecutarlo en el mysql me da el siguiente error:
Script line: 23 Can't create table 'projecte.pagina' (errno: 150)

No se que lo provoca y tampoco como solucionarlo, alguien me puede ayudar??
gracias