This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
Have you tried examining the request(s) sent to your web service that causes this error using Wireshark or similar program?
Then you could compare them (the requests that causes the error) with the requests from your standalone Java client to see what the difference is, if any.
I’ve looked at a lot of different solutions, and in my humble opinion Aspose is the way to go. Here’s the link: http://aspose.com
subject: org.apache.axis2.AxisFault: Server was unable to process request. ---> Object reference not set to a