diff --git a/system/database/DB.php b/system/database/DB.php
index 313728f..13a447d 100644
--- a/system/database/DB.php
+++ b/system/database/DB.php
@@ -158,12 +158,12 @@
 	// Check for a subdriver
 	if ( ! empty($DB->subdriver))
 	{
-		$driver_file = BASEPATH.'database/drivers/'.$param['dbdriver'].'/subdrivers/'.$params['dbdriver'].'_'.$params['subdriver'].'_driver.php';
+		$driver_file = BASEPATH.'database/drivers/'.$DB->dbdriver.'/subdrivers/'.$DB->dbdriver.'_'.$DB->subdriver.'_driver.php';
 
 		if (file_exists($driver_file))
 		{
 			require_once($driver_file);
-			$driver = 'CI_DB_'.$params['dbdriver'].'_'.$params['subdriver'].'_driver';
+			$driver = 'CI_DB_'.$DB->dbdriver.'_'.$DB->subdriver.'_driver';
 			$DB = new $driver($params);
 		}
 	}
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);
 	}
 
 	// --------------------------------------------------------------------