Some fixes
diff --git a/system/database/drivers/pdo/pdo_driver.php b/system/database/drivers/pdo/pdo_driver.php
index d18720e..824594f 100644
--- a/system/database/drivers/pdo/pdo_driver.php
+++ b/system/database/drivers/pdo/pdo_driver.php
@@ -57,7 +57,7 @@
 	protected $_count_string = 'SELECT COUNT(*) AS ';
 	protected $_random_keyword;
 
-	protected $trans_enabled = FALSE;
+	public $trans_enabled = FALSE;
 
 	// need to track the PDO options
 	public $options = array();
diff --git a/system/database/drivers/pdo/subdrivers/pdo_cubrid_driver.php b/system/database/drivers/pdo/subdrivers/pdo_cubrid_driver.php
index 2cab0f4..e4fae5a 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_cubrid_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_cubrid_driver.php
@@ -106,7 +106,7 @@
 	 */
 	protected function _list_columns($table = '')
 	{
-		return 'SHOW COLUMNS FROM '.$this->db->protect_identifiers($table, TRUE, NULL, FALSE);
+		return 'SHOW COLUMNS FROM '.$this->protect_identifiers($table, TRUE, NULL, FALSE);
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/pdo/subdrivers/pdo_mysql_driver.php b/system/database/drivers/pdo/subdrivers/pdo_mysql_driver.php
index fd7f327..b545338 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_mysql_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_mysql_driver.php
@@ -134,7 +134,7 @@
 	 */
 	protected function _list_columns($table = '')
 	{
-		return 'SHOW COLUMNS FROM '.$this->db->protect_identifiers($table, TRUE, NULL, FALSE);
+		return 'SHOW COLUMNS FROM '.$this->protect_identifiers($table, TRUE, NULL, FALSE);
 	}
 
 	// --------------------------------------------------------------------