ACS Down? Login has response 200 with empty body

Everything worked fine two days ago. Then I am receiveing HTTP-200 answers with empty body, like this:

==>login_admin: --- !ruby/object:Net::HTTPOK
body_exist: true
code: '200'
message: OK
body: ''
decode_content: true
uri:
header:
  server:
  - nginx/1.2.9
  date:
  - Tue, 17 Jun 2014 21:25:50 GMT
  content-type:
  - application/json; charset=utf-8
  transfer-encoding:
  - chunked
  connection:
  - close
  vary:
  - Accept-Encoding
  status:
  - '200'
  x-powered-by:
  - Phusion Passenger (mod_rails/mod_rack) 3.0.9
  access-control-allow-methods:
  - POST, GET, PUT, DELETE, OPTIONS
  access-control-allow-headers:
  - x-requested-with, Authorization, X-Titanium-Id
  access-control-allow-credentials:
  - 'true'
  etag:
  - '"229c1191386a7820f5d3ca4bee95c9bd"'
  cache-control:
  - max-age=0, private, must-revalidate
  x-ua-compatible:
  - IE=Edge,chrome=1
  set-cookie:
  - _session_id=scg_FjcYilUQh6HM-yedDS-Xyz8; path=/; HttpOnly
  x-runtime:
  - '0.100519'
socket:
http_version: '1.1'
read: true
==>login_admin: --- !ruby/object:Net::HTTPOK
body_exist: true
code: '200'
message: OK
body: ''
decode_content: true
uri:
header:
  server:
  - nginx/1.2.9
  date:
  - Tue, 17 Jun 2014 21:25:50 GMT
  content-type:
  - application/json; charset=utf-8
  transfer-encoding:
  - chunked
  connection:
  - close
  vary:
  - Accept-Encoding
  status:
  - '200'
  x-powered-by:
  - Phusion Passenger (mod_rails/mod_rack) 3.0.9
  access-control-allow-methods:
  - POST, GET, PUT, DELETE, OPTIONS
  access-control-allow-headers:
  - x-requested-with, Authorization, X-Titanium-Id
  access-control-allow-credentials:
  - 'true'
  etag:
  - '"229c1191386a7820f5d3ca4bee95c9bd"'
  cache-control:
  - max-age=0, private, must-revalidate
  x-ua-compatible:
  - IE=Edge,chrome=1
  set-cookie:
  - _session_id=scg_FjcYilUQh6HM-yedDS-Xyz8; path=/; HttpOnly
  x-runtime:
  - '0.100519'
socket:
http_version: '1.1'
read: true