Using pandoc, dzslides and mathjax only works with Firefox

Question

I'm trying to create dzslides with pandoc (v. 1.9.4.2) that contain equations which I want to be rendered by mathjax. Consider the following example:

% $\TeX$ test
% John Doe 
% March 22, 2013

## First slide

$$r_c(z) = \int_0^z\frac{{\rm d} z'}{H(z')}$$

## Second slide

- foo 
- bar 

Translate it with this command:

pandoc --mathjax -t dzslides -s textest.txt -o textest.html

Now, I'm using crunchbang waldorf, a Debian based Linux distro. In Opera 12.15 the equations don't appear at all, they're invisible. The mathjax script is loaded though, since I get that little message at the bottom when I load the slides. In Chromium 25.0.1364.160, the equations look all jumbled up. Only in Iceweasel 16.0.1 the equations look like expected.

I don't even know where this is going wrong. Is it a bug? Should I contact the developer of pandoc, dzslides, mathjax, or Opera (my browser of choice)?

Edit: I noticed that the second equation works when I remove font-size: 20pt; from the section CSS element. But then it doesn't have the right font size and the inline equation in the header still doesn't work.