when i run the spring-android-showcase i can't get the json result, but i can get the xml result through restTemplate. anybody can help me?

my showcase version is SpringSource-spring-android-samples-v1.0.0.RC1-40-gfb81900.zip

there are the Excepions when i Fetch Json list of states:
HttpGetJsonActivity(459): 406 Not Acceptable
because i can get the xml result, so I think the config will not be wrong.
who can resolve it, thank you...