fixing a series of errors in (ironically) error display in some database drivers
diff --git a/system/database/drivers/oci8/oci8_driver.php b/system/database/drivers/oci8/oci8_driver.php
index cd0e095..1ad05a7 100644
--- a/system/database/drivers/oci8/oci8_driver.php
+++ b/system/database/drivers/oci8/oci8_driver.php
@@ -244,7 +244,7 @@
 			if ($this->db_debug)
 			{
 				log_message('error', 'Invalid query: '.$package.'.'.$procedure);
-				return $this->display_error('db_invalid_query');
+				return $this->db->display_error('db_invalid_query');
 			}
 			return FALSE;
 		}
@@ -443,7 +443,7 @@
 	function insert_id()
 	{
 		// not supported in oracle
-		return $this->display_error('db_unsupported_function');
+		return $this->db->display_error('db_unsupported_function');
 	}
 
 	// --------------------------------------------------------------------