The bug.org file exhibits a discrepancy, which I believe to be a bug, between the LaTeX translation of an equation with a label on the same line and the same with a label on the following line. Or no label at all.
I have obtained this using a minimal setup (emacs -Q). Emacs : GNU Emacs 24.4.1 (x86_64-pc-linux-gnu, GTK+ Version 3.14.3) of 2014-10-25 on trouble, modified by Debian Package: Org-mode version 8.2.10 (release_8.2.10 @ /usr/share/emacs/24.4/lisp/org/) -- Laurent Steffan
#+TITLE: Possible bug in the LaTeX exporter
#+AUTHOR: Laurent Steffan
#+OPTIONS: tex:t toc:nil
\begin{equation*}\label{eq:dummy}
A_{\B_C}
\end{equation*}
\begin{equation*}
\label{eq:dummy}
A_{\B_C}
\end{equation*}
\begin{equation*}
A_{\B_C}
\end{equation*}
% Created 2014-12-12 ven. 10:42
\documentclass[11pt]{article}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{fixltx2e}
\usepackage{graphicx}
\usepackage{longtable}
\usepackage{float}
\usepackage{wrapfig}
\usepackage{rotating}
\usepackage[normalem]{ulem}
\usepackage{amsmath}
\usepackage{textcomp}
\usepackage{marvosym}
\usepackage{wasysym}
\usepackage{amssymb}
\usepackage{hyperref}
\tolerance=1000
\author{Laurent Steffan}
\date{\today}
\title{Possible bug in the \LaTeX{} exporter}
\hypersetup{
pdfkeywords={},
pdfsubject={},
pdfcreator={Emacs 24.4.1 (Org mode 8.2.10)}}
\begin{document}
\maketitle
\begin{equation*}\label{eq:dummy}
A$_{\B_{\text{C}}}$
\end{equation*}
\begin{equation*}
\label{eq:dummy}
A_{\B_C}
\end{equation*}
\begin{equation*}
A_{\B_C}
\end{equation*}
% Emacs 24.4.1 (Org mode 8.2.10)
\end{document}
bug.pdf
Description: Adobe PDF document
