Follow-up... After some more searching, I found this thread which seems to describe exactly what the problem is: http://www.opensubscriber.com/message/user@xmlbeans.apache.org/1601039.html
So it looks like this is a deficiency in XMLBeans, which is very disappointing. :( Anyway, I have resolved the issue by adding a regular expression parser which inspects the prefix that XMLBeans assigns to the namespace, then replaces it with the expected prefix. It's not what I would have preferred, but it does solve the problem. Thanks to the people who were kind enough to reply and provide assistance. I remain hopeful that this functionality will be added to XMLBeans in the future, since XMLBeans is in all other respects a very good library. Thanks, Justin