Is there any security we have to verify when using the SOAP Toolkit?

I have two very basic commands:

loWebService=Createobject("mssoap.soapclient30")
loWebService.mssoapinit("http://www.myserver.com/WebService/WebService.asmx?wsdl")

If I try that from the development environment to the development server, it works.
If I try that from the development environment to the UAT server, it works.
If I try that from the UAT environment to the development server, it does not work.
If I try that from the UAT environment to the UAT server, it does not work.

From DEV and UAT servers, the version of the SOAP Toolkit is the same.

From the UAT server, if I try to execute those commands, I get:

"Unexpected error OLE IDispatch exception code 0 from WSDLReader: WSDLReader:XML Parser failed at linenumber 0, lineposition 0, reason is: The download of the specified resource has failed. HRESULT=0x1: Incorrect function. - WSDLReader:Loading of the WSDL file failed HRESULT=0x80070057: The parameter is incorrect. - Client:One of the parameters supplied is invalid. HRESULT=0x80070057: The parameter is incorrect. .."