Fonts display problem with Firefox

English Applications
#1

Facing this problem with Firefox 4, kernel 2.6.38 (tumbleweed/Head), tried X11 update but problem still there…hovering over fonts correct it also Konqueror is fine with fonts…
http://i51.tinypic.com/2r45u83.jpg

#2

by the way using 11.4, KDE 4.6.1