Hey Adam,
same result with "da-DK".
From what I can see in line 1227 of the "include_CuteEditor.asp":
xmlfilename= Server.MapPath(GetURL("languages/"&s_culture&".xml"))
I assume the correct should be dk-da, since the file is called "dk-da.xml" - so perhaps a new dk-da.xml file could do the trick.
Sincerely,
Thomas