Hello,
I use org-mode (currently v7.9.3) to build materials for the courses I
teach.  I tend to use repeated underscores to indicate a blank, e.g.:
1) Fill in the _______.

Unfortunately, org-mode treats these as *successive* subscript requests,
and the text that follows is severely disrupted when exported via LaTeX.
 The local or global setting of `org-export-with-sub-superscripts' does not
seem to affect this behavior.

It seems appropriate that:
- no subscripting should occur in the above case
when `org-export-with-sub-superscripts' is set to nil or {}; and
- repeated underscores without any braces should probably not ever trigger
subscripting on export.

Thanks for all the continued work on org-mode!

--Nathaniel