It looks as if notes in a project are not saved along with the rest of the project history, so that when you revert to an earlier point in the project history, the notes you had at that point in history, are not restored. Although it is possible to get back some older notes by deleting Notes_.xml and renaming Notes_.xml.BAK to Notes_.xml, it seems to me that it would be better to be able to restore notes along with the rest of the project history. Is there any reason why that is not possible?