This might be due to a bug that has been fixed in 3.0.1 that caused the chunked encoding to be always disabled http://jira.jboss.com/jira/browse/JBWS-2000. The default jaxws client configuration has chunk size = 2048; if the server you're calling doesn't support chunked encoding, you might want to disable it setting the http://org.jboss.ws/http#chunksize property to 0 (zero) in the standard-jaxws-client-config.xml (or in your own config). I also suggest you to try using http/1.0 when .NET endpoints are involved and this kind of issues appear. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4156342#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...