[XeTeX] Problem with Japanese font

[Cyril Niklaus]

On 10 févr. 08, at 19:09, Gerrit Sangel wrote:
>
> \newcommand{\antiqua}[1]{{\setromanfont{Gentium}#1}}
> \newcommand{\kaiti}[1]{{\setromanfont{AR PL ZenKai
> Uni}\XeTeXlinebreaklocale "zh" #1}}
> \newcommand{\mincho}[1]{{\setromanfont{IPAMincho} 
> \XeTeXlinebreaklocale "ja"
> #1}}

Hello
Can't really help you here with the fonts, as their names come up  
garbled in os x 10.5.1 I can't select them.
But I did notice something strange in your preamble: why do you use  
the \setromanfont command to define fonts for Chinese and Japanese?
You should use the \newfontfamily command, eg:

   \newfontfamily{\mincho}{IPAMincho}

Cyril