pdo 与mysql 的问题，请教高手？

程序在window下正常，然而在linux下，
register:
public function Insert($input) {

$time = time ();

$sql = "  INSERT INTO " . __DB_PREFIX__ . "member(
`email`,
`password`,
`secrecy_email`,
`lock`,
`add_time`,
`last_login_time`
)VALUES(
'" . $input ['name'] . "',
'" . md5 ( $input ['password'] ) . "',
'" . $input ['email'] . "',
0,
" . $time . ",
" . $time . "
)";

$stmt = $this->prepare ( $sql );

if (! $stmt->execute ()) {
throw new Exception ( join ( ' ', $stmt->errorInfo () ) );
}
}
这个方法好用，但是：
public function Account($name, $password) {

$sql="select member_id from gm_member where email='mygirl' and password='25d55ad283aa400af464c76d713c07ad'";
//$sql = "SELECT member_id from " . __DB_PREFIX__ . "member WHERE email='" . $name . "' AND password='" . $password . "'";
//$sth = $this->prepare ( $sql );
//$sth->execute ();
$stmt = $this->prepare ( $sql );