difference between wsdl mode and non wsdl mode

Hi,

I am trying to develop a soap client in PHP using PHP5 SOAP Extension.
I am trying to connect to the webservices provided by Rollbase

The wsdl  url is http://www.rollbase.com/webapi/wsdl/rollbase.wsdl

When I connect to the web service in the wsdl mode, I am able to perform all the calls and everything works fine. I do it as follows

  $wsdl_url= 'http://www.rollbase.com/webapi/wsdl/rollbase.wsdl';
  $client = new SoapClient($wsdl_url, array('trace'=> true));

But if I connect in the non wsdl mode, like

$client = new SoapClient(null, array('location' => 'http://www.rollbase.com/webapi/services/rpcrouter', 'uri' => 'urn:Rollbase','style' => SOAP_RPC, 'use' => SOAP_ENCODED,'trace' => 1));

I am not able to make calls to the webservices because I hit Bad Types Exception when I send the parameters

To be more clear
In wsdl mode when I make a call like
 $result  = $soap_client->__soapCall('search', array(  'sessionId' =>$sessionID, 'query' => $query, 'objDefName' => $objname));

I get the resule as
object(stdClass)[2]
  public 'arr' =>
    object(stdClass)[3]
      public 'item' =>
        array
          0 => int '1995757' (length=7)
          1 => int '1995349' (length=7)
          2 => int '2097624' (length=7)
 You can note that the values are of type int(they are actually Long in Java)

But if I make the same call in non wsdl mode,  I get

object(stdClass)[2]
  public 'arr' =>
    object(stdClass)[3]
      public 'item' =>
        array
          0 => string '1995757' (length=7)
          1 => string '1995349' (length=7)
          2 => string '2097624' (length=7)

The values are string..
Also when I send parameters for making call, the types of the parameters matches the expected values in wsdl mode but in non wsdl mode i get the exception

SoapFault exception: [soapenv:Server.userException] org.xml.sax.SAXException: Bad types (class java.lang.String -> long)

My question  is what makes this difference, is there some other extra setting or parameter to set while performing non wsdl calls. what exactly is the difference between these 2 modes
Is there something wrong with the server that is providing this result (the server uses Axis)Start Free Trial