Thanks for your reply.

2014-10-13 2:45 GMT+02:00 Grant Rettke <gcr@wisdomandwonder.com>:

What version of Emacs and org mode are you using?

GNU Emacs 24.3.1

What is your configuration?

I'm using org from Elpa.

OS: At the moment Xubuntu 14.04 , but the same problem occurred with Debian testing.

What action did you perform on what document?

Here is a minimal document as example

#+OPTIONS: tex:imagemagick
#+TITLE: Minimal logic
#+AUTHOR: Joseph Vidal-Rosset

\begin{equation}
\neg A \to (A \to B)
\end{equation}

What did you want and expect to have happen with that action?

The export to latex works well.

BUT the export to html works BUT...

What happened instead?

produces always a corrupted png image for the equation. See the attachment.

Thanks for your help

Best wiishes

Jo.