Django's testserver returns JSON ok, but nginx returns junk

Django's testserver returns JSON ok, but nginx returns junk

i have nginx as a proxy to django default fcgi server.
The problem is django default server(manage runserver) works ok, but nginx
+ fcgi connection doesnt on returning JSON.Other types are ok - js,css,img
ok headers returned and json are.
default-



headers:
Content-Type:application/json
Date:Thu, 03 Oct 2013 01:02:05 GMT
Server:WSGIServer/0.1 Python/2.7.3
json:{"amount": 3000.0, "limit": 0.0,etc....}
nginx:



headers:
Connection:keep-alive
Content-Encoding:gzip
Content-Type:text/html; charset=utf-8
Date:Thu, 03 Oct 2013 01:04:03 GMT
Server:nginx/1.1.19
Transfer-Encoding:chunked
json - Ð'аланс
What or where can be the problem? Nginx config or may be