"Comment Fields" Not Displaying in Proper Order

This bug popped up when trying to modify the order of fields on the "Comment Fields" tab for a content type (in the case of article type, admin/structure/types/manage/article/comment/fields). Here are the relevant issues:

A. Regardless of where "Subject textfield" is designated to appear (above or below other fields), it is always appearing as the top field in the comment add form.

B. Changing the order of fields on the "Comment Fields" page is inadvertently changing the order of fields on the "Comment Display" page (admin/structure/types/manage/article/comment/display). This appears to be an issue not only with comments but with the Fields UI in general. (I first experienced this using the Private Message contrib module, which uses the Fields UI, then confirmed it also exists in core.)

Here's how you can reproduce:

1. Make a custom Comment field (image type) called "Comment Image."
2. On the "Comment Fields" page, place Comment Image above all fields (above "Author," "Comment," and "Subject").
3. On the "Comment Display" page, place Comment Image above all fields (above "Comment").
4. Go back to the "Comment Fields" page and move Comment Image below all fields. Then click "Save."
5. Now go back to the "Comment Display" page... Suddenly, Comment Image will be below Comment.

And I've confirmed that when viewing a comment, the order of fields have been re-arranged even though the site admin made no changes to the Comment Display page. Any idea what could be causing this? As far as I can tell, the Comment Fields page order affects the Comment Display page order, but not vice versa.

C. Aren't the "Author" and "Subject" fields supposed to appear on the "Comment Display" page (so that they can be re-ordered)? Currently, "Author" and "Subject" only appear on the "Comment Fields" page (even though "Comment" appears on both pages).

I hope all of this makes sense... let me know if it doesn't.

Thanks,
Ben