When editing the files to create locale specific translations, you must use an editor that understands and preserves the UTF-8 encoding. For basic editing we use Notepad++ which can edit files in UTF-8 and also contains conversion utilities. On opening an existing file, always check that the encoding has been set to UTF-8. Many editors will attempt to auto-detect the encoding, but if the file only contains basic ascii characters below X'80', there is no difference between an ascii and UTF-8 file and so the editor will probably not set the encoding format to UTF-8.
One way around this is to insert a BOM (byte order mark) at the start of the file to indicate the encoding, but this is not recommended for UTF-8 and we have decided not to include a BOM in the files generated by Rapide.