This is how a web page fragment shows on my old 11.04 system:
and this is how the same fragment showed on 11.10 and shows on my current 12.04 system:
Any idea what's wrong? Of course I have all the same fonts installed (I believe the page uses some kind of Arial, which I installed from the
mscorefontstt package IIRC) and I'm running the same version of Firefox. How can I fix things?