Removing internal references to the EXT constant.  Additionally, marked the constant as deprecated.  Use ".php" instead. Also adding upgrade notes from 2.0.2 to 2.0.3.
diff --git a/system/database/DB_driver.php b/system/database/DB_driver.php
index e7a9de4..10e8ed0 100644
--- a/system/database/DB_driver.php
+++ b/system/database/DB_driver.php
@@ -424,8 +424,8 @@
 
 		if ( ! class_exists($driver))
 		{
-			include_once(BASEPATH.'database/DB_result'.EXT);
-			include_once(BASEPATH.'database/drivers/'.$this->dbdriver.'/'.$this->dbdriver.'_result'.EXT);
+			include_once(BASEPATH.'database/DB_result.php');
+			include_once(BASEPATH.'database/drivers/'.$this->dbdriver.'/'.$this->dbdriver.'_result.php');
 		}
 
 		return $driver;
@@ -1115,7 +1115,7 @@
 
 		if ( ! class_exists('CI_DB_Cache'))
 		{
-			if ( ! @include(BASEPATH.'database/DB_cache'.EXT))
+			if ( ! @include(BASEPATH.'database/DB_cache.php'))
 			{
 				return $this->cache_off();
 			}