[Mediawiki-l] Math rendering problems

[Erik Moeller]

On my wiki (MW 1.5.5),

<math>x_{1,2}=\frac{-b\pm\sqrt{b^2-4ac}}{2a}</math>

is rendered like this:

http://www.adciv.org/upload/math/0f16872ccd04ca7ecce3544bc3521ff1.png

while it should be rendered like this:

http://en.wikipedia.org/math/0/f/1/0f16872ccd04ca7ecce3544bc3521ff1.png

Any idea where I should look to fix this? It's a Debian Stable 
installation, with the whole texvc toolchain set up.

Thanks,

Erik