Added dummy _reset_select() method to CI_DB_Driver class to allow Active Record class to be disabled. Otherwise a fatal error is triggered.
diff --git a/system/database/DB_driver.php b/system/database/DB_driver.php
index 3680b85..8f530b4 100644
--- a/system/database/DB_driver.php
+++ b/system/database/DB_driver.php
@@ -1381,7 +1381,21 @@
 
 		return $item.$alias;
 	}
+	
+	// --------------------------------------------------------------------
 
+	/**
+	 * Dummy method that allows Active Record class to be disabled
+	 *
+	 * This function is used extensively by every db driver.
+	 *
+	 * @access	private
+	 * @return	void
+	 */
+	protected function _reset_select()
+	{
+	
+	}
 
 }