Nusoap and Xul

Hello,

I'm trying to use a web service build with nusoap in FireFox,
but the answer of the server has an error:
XML Parsing Error: xml declaration not at start of external entity
Location: http://ippous.dyndns.org/passxul/compte.php3

The XML seems to be well formed:
<?xml version="1.0" encoding="ISO-8859-1"?><SOAP-ENV:Envelope SOAP-ENV:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/" xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:SOAP-ENC="http://schemas.xmlsoap.org/soap/encoding/" xmlns:si="http://soapinterop.org/xsd" xmlns:tns="urn:EjaumTest"><SOAP-ENV:Body><ns1:ListerComptesResponse xmlns:ns1="urn:EjaumTest"><return xsi:type="SOAP-ENC:Array" SOAP-ENC:arrayType="tns:CompteDes[2]"><item xsi:type="tns:CompteDes"><Compte xsi:type="xsd:string">Test1</Compte><Id xsi:type="xsd:int">1</Id></item><item xsi:type="tns:CompteDes"><Compte xsi:type="xsd:string">Test2</Compte><Id xsi:type="xsd:int">2</Id></item></return></ns1:ListerComptesResponse></SOAP-ENV:Body></SOAP-ENV:Envelope>

I do not unterdand.
Has somebody an explication ?

Regards.