How to publish Facebook page updates using ruby ​​fb_graph?

I just wanted to automate Facebook posts for specific events on my corporate Facebook page. It seems that this should be clear from what I have read so far, however I ran into an obstacle.

The code sample that I have and the error is as follows:

  user = FbGraph::User.me(access_token)
  user = FbGraph::User.fetch('PageName')
  FbGraph.debug! # yields true
  user.feed!(
    :message => 'Updating via FbGraph',
    :link => 'https://domain.tld',
    :name => 'PageName',
    :description => 'This is a test post to be deleted'  
  )

This returns the following error:

======= [FbGraph] API REQUEST STARTED =======
POST /234062246478665/feed HTTP/1.1
Content-Type: application/x-www-form-urlencoded
Content-Length: 124
Host: graph.facebook.com

message=Updating+via+FbGraph&link=https%3A%2F%2Fdomain.tld&name=PageName&description=This+is+a+test+post+to+be+deleted
--------------------------------------------------
Status: 403 Forbidden
Access-Control-Allow-Origin: *
Cache-Control: no-store
Content-Type: text/javascript; charset=UTF-8
Expires: Sat, 01 Jan 2000 00:00:00 GMT
Pragma: no-cache
WWW-Authenticate: OAuth "Facebook Platform" "insufficient_scope" "(#200) This API call requires a valid app_id."
X-FB-Rev: 541309
X-FB-Debug: JN9/Vt8MN24GNUL34l8TE2cDuCRZZehdUTx2KkOrHQ8=
X-Cnection: close
Date: Mon, 16 Apr 2012 18:55:20 GMT
Content-Length: 0

{"error":{"message":"(#200) This API call requires a valid app_id.","type":"OAuthException","code":200}}
======= [FbGraph] API REQUEST FINISHED =======
/Users/username/.rvm/gems/ruby-1.9.3-p125@all/gems/fb_graph-2.4.10/lib/fb_graph/exception.rb:55:in `handle_httpclient_error': OAuthException :: (#200) This API call requires a valid app_id. (FbGraph::Unauthorized)
    from /Users/username/.rvm/gems/ruby-1.9.3-p125@all/gems/fb_graph-2.4.10/lib/fb_graph/node.rb:145:in `handle_response'
    from /Users/username/.rvm/gems/ruby-1.9.3-p125@all/gems/fb_graph-2.4.10/lib/fb_graph/node.rb:54:in `post'
    from /Users/username/.rvm/gems/ruby-1.9.3-p125@all/gems/fb_graph-2.4.10/lib/fb_graph/connections/feed.rb:15:in `feed!'
    from ./test_script.rb:168:in `block in <main>'
    from /Users/username/.rvm/gems/ruby-1.9.3-p125@all/gems/nokogiri-1.5.2/lib/nokogiri/xml/node_set.rb:239:in `block in each'
    from /Users/username/.rvm/gems/ruby-1.9.3-p125@all/gems/nokogiri-1.5.2/lib/nokogiri/xml/node_set.rb:238:in `upto'
    from /Users/username/.rvm/gems/ruby-1.9.3-p125@all/gems/nokogiri-1.5.2/lib/nokogiri/xml/node_set.rb:238:in `each'
    from ./test_script.rb:85:in `each_with_index'
    from ./test_script.rb:85:in `<main>'

On developers.Facebook.com/apps → Settings → Auth Dialog I set Extended Permissionsto enable publish_streamand status_update.

I found that accessing curlwith the same token really works as follows:

curl -F 'access_token=MY_BIG_OLE_LONG_TOKEN' -F 'message=testing message' https://graph.facebook.com/MyPage/feed

Am I skipping setting any permission or not correctly calling api with fb_graphruby gem ?