A problem was found and fixed in the Chilkat.CkString utility class (which is a freeware class).
The HTML entity decoding method was not decoding Unicode decimal entities such as П
This example shows how to decode a Bulgarian string that says "Hello":
Chilkat.CkString cks = new Chilkat.CkString();
cks.setString("Привет
");
cks.entityDecode();
MessageBox.Show(cks.getString());
This is available as a pre-release. The next official release after 11-July-2007 will include this new functionality.