My configuration is : 
 - RedHat8
 - Apache 2.0.43
 - PHP 4.3.1-dev (same problem with PHP 4.4.0-dev, PHP 5.0.0-dev ; PHP 4.3.0 have another annoying problem)

I have IP stored in a db in longint format (with ip2long(...)).
I use the following script to obtain the hostname of an IP.

<?
$entier = $_POST[entier];
//print_r($_POST); // To view the bug
print "<form action=ip.php method=post name=conversion>";
print "<input type=text name=entier value=$entier>";
print "<input type=submit value=Convertir>";
print "</form><br><br>";
$ip = long2ip($entier);
print $ip;
print "<br>".gethostbyaddr($ip);
?>

For example, if I type -722987112, I want to obtain 212.232.23.152 with the good hostname.

I have this problem : 
if I perform a print_r($_POST), I obtain : 
Array ( [entier] => -722987112entier=-722987112 )

The script worked fine with Apache 1.2.27/PHP 4.2.3