$_SERVER["HTTP_CLIENT_IP"] causes error in FastCGI mode

So, I have a piece of code that worked perfectly up until now, that is, under ISAPI mode.

Now I have installed PHP in FastCGI and the following code no longer works:

$cip = $_SERVER["HTTP_CLIENT_IP"] ;

The PHP version is 5.2.9-2 for both installations (the old ISAPI and the current FastCGI).

The error thrown:

Client found response content type of '', but expected 'text/xml'. The request failed with the error message: -- PHP Warning: Call-time pass-by-reference has been deprecated in C:\inetpub\wwwroot\TEST\WS\wsdatahandler.php on line 781 PHP Warning: Call-time pass-by-reference has been deprecated in C:\inetpub\wwwroot\TEST\WS\wsdatahandler.php on line 781 PHP Warning: Call-time pass-by-reference has been deprecated in C:\inetpub\wwwroot\TEST\WS\wsdatahandler.php on line 894 PHP Warning: Call-time pass-by-reference has been deprecated in C:\inetpub\wwwroot\TEST\WS\wsdatahandler.php on line 897 PHP Warning: Call-time pass-by-reference has been deprecated in C:\inetpub\wwwroot\TEST\WS\wsdatahandler.php on line 897 PHP Notice: Undefined index: HTTP_CLIENT_IP in C:\inetpub\wwwroot\TEST\WS\wshandler.php on line 225 PHP Notice: Undefined index: HTTP_X_FORWARDED_FOR in C:\inetpub\wwwroot\TEST\WS\wshandler.php on line 225 --.

PHP version is unchanged, IIS is unchanged.

What could be the root of the problem???