I use Kubuntu Gutsy (yes, i'm waiting to upgrade) and Firefox (126.96.36.199) has problems displaying Indic (Indian) scripts such as Hindi and Kannada.
I can see the individual letters (Unicode or UTF-8) but they are split apart. That is "ki" is not displayed as a single ligature but two separate glyphs (i.e, k is not combining with i)
I have installed all the latest fonts (ttf-indic-*) but still the problem persists. Any help ?