xmlrpc error faultCode 105 faultString XML error: Invalid document end at line 1, column 1

Hi,

I am trying to use xmlrpc to set up a client/server connection. I used
PHP5 in Apache2, with xmlrpc.inc downloaded from http://phpxmlrpc.sourceforge.net/,
which is created by Edd Dumbill.

Client side is:

require_once('xmlrpc.inc');
$c = new xmlrpc_client("http://localhost:84/server.php");
$c->setDebug(1);
$m = new xmlrpcmsg('fns_test', array(new xmlrpcval(20, "int")));
$r = $c->send($m);
echo $r->serialize();
?>

Server side is:
include("xmlrpc.inc");
include("xmlrpcs.inc");

$findstate_sig=array(array($xmlrpcString,$xmlrpcInt));
$findstate_doc="find state name based on name";
$s=new xmlrpc_server(
array(
"fns_test" => array(
"function" => "findstate1",
"signature"=>$findstate_sig,
"docstring"=>$findstate_doc
)
)
);
$s->setDebug(2);
function findstate1($m)
{
$sname="WashingTon"; return $sname;
// return new xmlrpcresp(new xmlrpcval($sname));
}
?>

I have already simplified the code to the minimum, but when I run the
client, I always got following error:

faultCode 105 faultString XML error: Invalid document end at line 1,
column 1

I googled a lot, but no relevant result. Does anyone have this
relevant error when setting up server side? From the fault string,
this might be the xml format error, but I only use the xmlrpc client
to send request, no other string sent by myself..

Thanks anybody for reading this thread and your help is appreciated.

Frank