Displaying DOS characters from Clip Library

[wisebytes]

I do not understand the instruction:

On Windows XP, edit controls in dialog boxes do not display characters in the same font script as the active document, unless it matches the the language selected for non-Unicode programs, using Control Panel's Regional and Language Options.

When I select a "Dos character" from the Clip Library, I get some strange character (usually a black block) even though the correct character is added to the file (as demonstrated when I view the file with another program). I am using Windows XP Pro on a Sony Vaio and am located in California.