Added CI_ Prefix to the Cache driver.
diff --git a/system/libraries/Cache/drivers/Cache_file.php b/system/libraries/Cache/drivers/Cache_file.php
index 86d1a3b..13e2d1a 100644
--- a/system/libraries/Cache/drivers/Cache_file.php
+++ b/system/libraries/Cache/drivers/Cache_file.php
@@ -25,7 +25,7 @@
  * @link		
  */
 
-class Cache_file extends CI_Driver {
+class CI_Cache_file extends CI_Driver {
 
 	protected $_cache_path;