Hi,
in the Wysiwyg, there is an insert special character tool but the only character I have is: À.
What needs to be done to get the other special chars?
Cheers.
By default they should all be there. There isn't any way through the admin interface to decide which chars are turned on, and off - you can only disable or enable the wysiwyg plugin. The file that stores the code to build them just lists the entities in a simple array:
/path/to/matrix/fudge/wysiwyg/plugins/special_chars/char_map.php
If it isn't displaying properly there is a possiblity it could be a bug, unless your browser type is not setup to display the HTML entities.
The source code of the popup windows finishes with:
| À |
Please log this as a bug. 
Done: bug #1311.
The bcmod() function has been removed in favour of the plain '%' modulo function. Will be in the 3.8.2 release due out today.