webMethods Bigmachines API Invocation Issue

We have an integration with the following design flow:

  1. Bigmachines(Cloud based CRM) starts the integration by invoking the http URL of the main flow service, and sends input XML payload.
  2. webmethods uses the data from the input XML and fetches corresponding data from an ERP (using a SOAP webservice).
  3. webMethods then uses the data obtained as the output of the WS to update the same to Bigmachines. It does this by calling the Bigmachines API (which is a set of SOAP services).
  4. After all the services (in the API) are succesfully invoked by WM, it closes the original http connection with bigmachines. Thus it is a synchronous http based integration.

In the above flow, we are facing the following situation:

  1. webMethods is able to invoke all the Bigmachines’ services and get a success response from them, however, some of the webservices (although they return a success response), are not able to function correctly, because they seemingly are not getting the data fields from webMethods.
  2. However, when i run the webMethods flow service manually (by using save/restore pipeline) the second time, everything works the way it should.
  3. I am able to reproduce this issue consistently over and over again, i.e.bigmachines sends the request to webmethods using http, i use savepipeline and simply return a dummy response to bigmachines (and the flow execution is over). I then manually run the service (by using restorePipeline), and everything works as it should.
    4)The webservice consumer connectors used to call the Bigmachines services also work fine when they are run standalone, i.e. they return a success response AND the service does what it should on the BM end.
  4. Based on the consistent occurrence of the issue, i am concluding that bigmachines is not receiving the data from webMethods when the APIs are invoked by webMethods in the same IS session. However, when the APIs are called in a different IS session (by using restorePipeline), everything works as it should.

We are investigating this issue from the Bigmachines’ side as well but i would like to know if any WM experts here could have any ideas or suggestions or comments. We are using WM 7.1.3.