The concept of "tags" that I suggested was a potential solution. Instead of grouping stories into Themes, you can "tag" a given story with one (or more) themes. (Check out GMail's "labels").

This would allow users to group stories by theme, or simply show the entire sorted backlog. It would also allow stories to have more than one theme. For example, some of our themes are: Art, Engineering, Design, Leaderboards, Frontend, Backend. Many of our stories fall under multiple themes.

Hope that helps. Let me know if you need more clarification. You guys are doing an awesome job and your reaction time to my feedback is impeccable.

Thanks again!

If I have Acceptance Criteria that already contains line breaks, when I go back in to edit the acceptance criteria, all existing line breaks are removed.

Thanks!