Please give some more details.
Is the service service running in Integration Server?
What is the client?
Is it being invoked via a SOAP RPC SoapRequest going to the /soap/rpc URL?
What is in the service pipeline when the service is complete?
If x is in the pipeline with an empty string as the value then should go into the Soap Response.
If x is in the pipeline with an empty string as the value then or should go into the Soap Response.
Also, with IS_4-6_SP1 Soap Responses always contain the xsi:type field, even if nil, in order to interoperate with the maximum number of Soap implementations.
#Integration-Server-and-ESB#webMethods#webMethods-General