We have been using JIRA for many years now, and are generally a happy client. I should have filed this issue years ago, but recently this was brought to my attention again.
We use attachments extensively, and we even introduced guidelines for the naming of attachments so they're ordered the way we want to. But this proves unworkable in the long run. Therefore, the enhancement request is to make it possible to order attachment in various ways, such as name, creation date, modification date, etc. This sorting should stay in effect across issues (i.e. it is not issue specific).