XI Response is not received

I am trying to retrieve information from an oracle database for updating an object on my portal application. But for some reason, I receive a null value instead of the information I am expecting.

I have verified that I am sending the proper XML document to XI. Also I have verified that XI is generating the desired response in a form of XML. However in my HTMLAdapter, my input stream receives null instead of the response generated by XI.

Any ideas of why this is happening.