In the RH Help, topic "WebHelp browser and platform
limitations,"
Platform limitations:
Macintosh
* Macintosh has a 32-character file name limit. If you have
long topic titles with matching long file names, the topics will
not be viewable on a Macintosh.
* Output displays as HTML lists instead of using Dynamic HTML
or Java applets.
* .BMP image files do not display properly. Use .GIF or .JPG
image files.
See also their topic "About generating WebHelp with different
options." There's stuff in these topics about using the Pure HTML
option for those platforms/browsers that don't fully support
Dynamic HTML, which might apply here.
Good luck,
Leon