Error when trying to restore my database

[kurtmorrison]

i'm getting this error code:

#1005 - Can't create table './*******_vbulletin/boxmail.frm' (errno: 150)

And this is the SQL consult:

CREATE TABLE `boxmail` (
`id_mail` int( 6 ) NOT NULL AUTO_INCREMENT ,
`id_group` int( 4 ) NOT NULL default '0',
`mail` varchar( 50 ) NOT NULL default '',
PRIMARY KEY ( `id_mail` ) ,
UNIQUE KEY `mail` ( `mail` ) ,
KEY `id_group` ( `id_group` ) ,
CONSTRAINT `boxmail_ibfk_1` FOREIGN KEY ( `id_group` ) REFERENCES `groupfull` ( `id_group` ) ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE = InnoDB DEFAULT CHARSET = latin1;

WTF is happening? can you help me