The firefox 3.6.23 works for me, I use tcpdump to dump the message, it's
HTTP/1.1 200 OK
So the Content-Type is correct here.
For chrome, I believe you hit a known issue described here.
Btw, use browser to send request is just for test purpose, we also provide a java code client, do
mvn compile exec:java
which will use java code client to send the request.