Grid font (Tools=>Options=>General)
The default font used by the GSAK grid is "MS Sans Serif", and unfortunately this font (like most) does not display all characters (the emdash being one of them). For example:
If you are in a country where it is common for cache names to contain characters that do not display correctly, you can select a font that best displays these characters. In the example above, the font "Arial" will correctly display the emdash.