This issue is still present (successfully reproduced with Firefox 24.0, Windows 7 SP1 - x86).
Still no error in the log, besides a "XUL box for a element contained an inline #text child, forcing all its children to be wrapped in a block" message, pertaining to prefs.xul.
This issue is still present (successfully reproduced with Firefox 24.0, Windows 7 SP1 - x86).
Still no error in the log, besides a "XUL box for a element contained an inline #text child, forcing all its children to be wrapped in a block" message, pertaining to prefs.xul.