Using debian wheezy and iceweasel, I somehow managed to have it no longer redering text in pre tags. It still shows the background but no text. This is no color problem, I cannot select anything. I can see the code using "show selection source".
I have already tried reinstalling the iceweasel package, and running in safe mode, but to no avail.
As a sidenote, it might be more than just pre, the textarea for asking and answering questions on stackechange have it also. The cursor just stays in the left of the textarea and I only see what I am typing thanks to the instant preview.
Recent changes to my system is that i tried to install monospace fonts like consolas and inconsolata, which failed (they show as boxes), and that I played around with the system default fonts in gnome tweak tool... However changing settings doesn't resolve the problem on first sight...
Tor browser bundle, which has a completely different profile as well as executables also has it.
I tested by making some monospace text with css and it still shows monospace fine... Another textarea on a site I am building works fine, I don't know what is special about the ones on stack exchange.
I know I am very talented in making software break, but it is really incredible how it can break in such ridiculous ways though...
Any clues more than welcome, I am flabbergasted.