Problems with formulae

I use Xerte for more than a year and until recently I had no major problems.
With version 2.1 I used latex expressions for formulae and inserted tags like:

<tex alt="dP/dz=ρg" src="{\frac{dP_{hst}}{dz}= \rho g}"></tex>

This worked fine for most of the time. Recently, I noticed that my deployed e-learning projects from last year refuse to render any formula. I assumed that the MathJax service changed something. I decided to install Xerte 3.1 and hoped to resolve this problem quickly. I figured out that I had to change the syntax a little bit:

<span class="mathjax">\[\frac{dP_{hst}}{dz}= \rho g\]</span>

So, now the formulae are rendered correctly in the XERTE editor. However, if I export a deployment folder and open it in firefox then no latex expression is rendered. It appears that MathML expressions are rendered, only. But MathML doesn't seem to work with MS-browsers.
What would be the best way to ensure that formulae in the deployment folders are rendered properly in any browser?

Regards,
Thorsten

The <tex> syntax depends on an external service that runs on one of my servers. Ir converts the expression in an image and inserts the image in the html. We recently had a security breach on that server, and that is probably the reason why it doesn't work any more. I'll look into that.

The Mathjax syntax is indeed the best way to do this, as it uses javascript and proper fonts to render the formula. It therefore scales much better than the image heneragtion.

Did you try to open the deployment package from disk, or was it installed and loaded in firefox from a webserver. The latter should have worked. The former should also work if you export the LO as an offline package.

Dear Tom,
thanks for your advice. I opened index.html from disk since I would like to store the LO on memory stick for presentations or send them via email. The option "offline Archive" works perfectly for both, MathML and Latex. Thank you very much.

Kind regards,
Thorsten