This seems to be related to cairo (used by xulrunner-1.9), or more precisely, to one of the patch used by Ubuntu (as the embedded cairo shipped by Mozilla is not affected). Most probably the lcd subpixel filter patch.
Strangely, those rendering errors seem to occur only on ATI when using XAA (confirmed on fglrx and radeon X drivers).
This seems to be related to cairo (used by xulrunner-1.9), or more precisely, to one of the patch used by Ubuntu (as the embedded cairo shipped by Mozilla is not affected). Most probably the lcd subpixel filter patch.
Strangely, those rendering errors seem to occur only on ATI when using XAA (confirmed on fglrx and radeon X drivers).