SOAP_WSDL stop working since changing the server

I have a working website on a pre-production server, all functions are responding correctly. The site uses SOAP to request our clients server.

It uses two basic functions, one for searching items and other one to get the details of an specific item. Since I've installed the website into the production server, the search one just return "null" (the other one works fine).

I use pear SOAP 0.12.0. http://pear.php.net/package/SOAP/

Here's an example of the code:

include_once("./SOAP/Client.php");
$wsdl = new SOAP_WSDL('http://webservice.homeresa.com/WebHR.asmx?WSDL');
$getservice = $wsdl->getProxy();
$results = $getservice->Function($var1, $var2, $var3);

Has anyone any idea of what's happening? Am I missing something?

Also, is it possible to debug someway the SOAP calls?

Thanks in advance.

Ok, my client forgot to tell me that there's one pdf with documentation about the webservice. It was IP restricted, so... that was the problem. I contacted them to allow the new host.