FreeSerif is the default Serif font in Firefox & epiphany on Karmic, this font has unreadable glyphs for Persian and maybe other nonlatin languages...
Jaunty didn't have this bug.
pmap grep ttf for firefox in Jaunty CD is:
b2285000 316 - - - r---- DejaVuSansMono.ttf
b2419000 300 - - - r---- DejaVuSerif-Bold.ttf
b24be000 560 - - - r---- DejaVuSans-Bold.ttf
b4051000 324 - - - r---- DejaVuSerif.ttf
b48eb000 608 - - - r---- DejaVuSans.ttf
and pmap grep ttf for firefox in Karmic CD is:
aebc7000 1252 - - - r---- FreeSerif.ttf
b5628000 300 - - - r---- DejaVuSerif-Bold.ttf
b5673000 560 - - - r---- DejaVuSans-Bold.ttf
b60ad000 324 - - - r---- DejaVuSerif.ttf
b723a000 608 - - - r---- DejaVuSans.ttf
Screenshot for Jaunty which looks fine: http://launchpadlibrarian.net/34758919/Screenshot-Jaunty.png
Screenshot for Karmic which is unreadable: http://launchpadlibrarian.net/34759310/Screenshot-Karmic.png
From what I see in both Jaunty and Karmic the language- support- fonts-fa depends on ttf-farsiweb and ttf-sil- scheherazade
Also it looks like Nazli font is shiped with ttf-farsiweb
Basicaly, from the point of view of Persian language support there were no changes between Jaunty and Karmic.
Maybe there is a problem with default fonts configuration in GNOME or Firefox.
I have assigned the Ubuntu Persian Translation team. Please advice with this problem.
Thanks!