Soap Receiver adapter - 401 error

Question

I am getting following error with soap receiver,
com.sap.engine.interfaces.messaging.api.exception.MessagingException: SOAP: response message contains an error XIAdapter/HTTP/ADAPTER.HTTP_EXCEPTION - HTTP 401 Unauthorized
I am able to consume the webservice with SOAP UI without any difficulty. I have tried with both the endpoint URL and WSDL url without success. I have tried with/without 'Do not use SOAP envelope'. I am not sure what is wrong. When the message is sent via PI, he is not able to look at the payload (while performing the trace) , while he is able to view the actual soap message with SOAP UI.
When i type the ENDPOINT url in my http address, i get a 'page not found' error.
Any ideas as to what i could be missing?

Answer 1

One more interesting behaviour when I was sending from SOAP UI, The request was posted twice, meaning there were two POST actions in my TCPGATEWAY listening port, while there was only one request via PI.
Wnen my partner put a trace, the SOAP envelop was missing in their TRACE for PI file while the SOAP envelop was available for SOAP ui message (in the second request). Could it have something to do with a fact that we are doing HTTP 1.1with soap uI While PI is HTTP 1.0 (HTTP 1.1 being a persistent connection resulting in second request)
Trace on the partner side,
PI Message 
POST /Services/Calculator/Version1/Calculator.asmx HTTP/1.0
accept: * / *
host: www.html2xml.nl
user-agent: SAP-Messaging-com.sap.aii.af.sdk.xi/1.0505
callingtype: SJM
content-id: <soap-4EB90CC8537E011DE1008000CDEB6913>
content-type: text/xml; charset=utf-8
content-length: 888
SOAPAction: "http://tempuri.org/Add"
HTTP/1.0 401
WWW-Authenticate: Basic realm="CASM"
Content-Type: text/html;charset=utf-8
Content-Length: 40
Date: Thu, 10 Nov 2011 11:50:13 GMT
Connection: close
SOAP UI log
POST /Services/Calculator/Version1/Calculator.asmx HTTP/1.1
accept-encoding: gzip,deflate
content-type: text/xml;charset=UTF-8
soapaction: "Create"
user-agent: Jakarta Commons-HttpClient/3.1
host: www.html2xml.nl
content-length: 2496
HTTP/1.1 401
WWW-Authenticate: Basic realm="CASM"
Content-Type: text/html;charset=utf-8
Content-Length: 40
Date: Thu, 10 Nov 2011 12:04:40 GMT
POST /Services/Calculator/Version1/Calculator.asmx HTTP/1.1
accept-encoding: gzip,deflate
content-type: text/xml;charset=UTF-8
soapaction: "Create"
user-agent: Jakarta Commons-HttpClient/3.1
content-length: 2496
authorization: Basic U1lTX1dFQl9TQVBQSTo=
host: www.html2xml.nl
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/";
</soapenv:Envelope>
HTTP/1.1 200
Set-Cookie: JSESSIONID=A48C8808315935EFD7AFBA8B4B96FC62; Path=/xx
Keep-Alive: timeout=1200000, max=1000
Connection: Keep-Alive
Content-Encoding: gzip
Content-Type: text/xml;charset=utf-8
Content-Length: 2882