The following happens to me using Firefox 5.0 on OS X 10.6.7, but also on Firefox 4.0.3 (with all plugins disabled and emptied cache, restarted etc). It doesn't happen with Safari 5.0.5, though.
Until recently, right-clicking on a formula and selecting "show source" yielded a pop-up window showing the LaTeX-source. For instance, the very simple formula
$$\max{\{a,b\}} = \frac{a+b}{2} + \frac{|a-b|}{2}$$
appearing in this answer was created using
\max{\{a,b\}} = \frac{a+b}{2} + \frac{|a-b|}{2}
Right-clicking on the formula (on the main site!) and selecting "show source" now yields the following human-unreadable garbage (excerpt of about a screen full of similar lines)
<math xmlns="http://www.w3.org/1998/Math/MathML" display="block">
<mo movablelimits="true">max</mo>
<mrow>
<mo fence="false" stretchy="false">{</mo>
<mi>a</mi>
<mo>,</mo>
<mi>b</mi>
<mo fence="false" stretchy="false">}</mo>
</mrow>
...
On the meta site, we still have the desired result. Could this please be re-installed on the main site, because this feature is very useful for referring LaTeX-unsavvy users to, while the new result is of no use, really.
