Request body in a module (no replies)

Hi, have been trying to read the request body in my module, using the information I have gotten from this forum and some blogs and basically came up with the following functions
as can be seen in this post http://forum.nginx.org/read.php?11,245953. The problem is that the request_body.bufs seem to contain no data.

If I check the request body with the following conf:

log_format my_tracking $request_body;


location /dd {
access_log logs/postdata.log my_tracking;
proxy_pass http://127.0.0.1:8081/temp_service;
}

location /demo {
access_log logs/postdata.log my_tracking;
demo;
}

I get the request_boody logged in the first /dd post request but in the second /demo I do not get anything logged if I post data
Use the following command the trying it out: curl -v --request POST -d "a=b" http://localhost:8080/dd
Anyone that have an idea what can be wrong?

Best Regards
Christer