The last caractere of the output is replace by a \0 when I use CURLOPT_RETURNTRANSFER with curl

I know the the bug is supposed to be fix for WIndows OS... but i still have the problem under Linux

You can see the problem in this little script

INPUT: ALLO

<?php
$ch = curl_init("https://www.secure-ssl.net/secure.iwebreservation.com/output.php");
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, "output=allo");
curl_setopt($ch, CURLOPT_RETURNTRANSFER,1); 
curl_setopt($ch,URLOPT_VERBOSE,1);
$toto =  curl_exec ($ch);
curl_close ($ch);

echo "[$toto]<br>";

for ($i=0;$i<strlen($toto);$i++)
 echo "$toto[$i] -".ord($toto[$i])."<br>";

?>

Output:
[all]
a -97
l -108
l -108
-0