load config files from environment specific locations in core classes, helpers and libraries
diff --git a/system/libraries/User_agent.php b/system/libraries/User_agent.php
index 3774fc2..2690e17 100644
--- a/system/libraries/User_agent.php
+++ b/system/libraries/User_agent.php
@@ -84,7 +84,16 @@
 	 */
 	private function _load_agent_file()
 	{
-		if ( ! @include(APPPATH.'config/user_agents'.EXT))
+		if (file_exists(APPPATH.'config/'.ENVIRONMENT.'/user_agents'.EXT))
+		{
+			$_ua_path = APPPATH.'config/'.ENVIRONMENT.'/user_agents'.EXT;
+		}
+		else
+		{
+			$_ua_path = APPPATH.'config/user_agents'.EXT;
+		}
+	
+		if ( ! @include($_ua_path))
 		{
 			return FALSE;
 		}