[XeTeX] Hyperref problem

[jropers@freesurf.fr]

Hello,

With the help provided here, I managed to have a working install of 
Xetex under win32 (big thanks to those that make that possible).

Now I'm trying to produce a pdf using hyperref to have sections 
displayed as bookmarks.
Although the text is correctly typeset with the chosen fonts (thanks 
fontspec !), the bookmarks are rendered as illegible squares.

How can I get the bookmarks correctly rendered ?

Thanks,

Jacques.