Index: lib/twitter/client/base.rb
===================================================================
--- lib/twitter/client/base.rb	(リビジョン 1274)
+++ lib/twitter/client/base.rb	(作業コピー)
@@ -69,6 +69,7 @@
       @@http_header ||= { 
       	'User-Agent' => "Twitter4R v#{Twitter::Version.to_version} [#{@@config.user_agent}]",
       	'Accept' => 'text/x-json',
+      	'Content-Type' => 'application/x-www-form-urlencoded',
       	'X-Twitter-Client' => @@config.application_name,
       	'X-Twitter-Client-Version' => @@config.application_version,
       	'X-Twitter-Client-URL' => @@config.application_url,