Problems with HSSF and character sets

[Alain Mowat]

    Hello,
    I'm having problems using HSSF with czech files, and probably other 
languages that have special characters in them. 
    If I open a file, and then simply write this same file to the hard disk 
with no modification whatsoever, the saving process actually modifies a certain 
number of characters and replaces them by a '?'. 
    This happens with the following simple code : 
        POIFSFileSystem fs = new POIFSFileSystem(new FileInputStream("Path to 
file"));

        wb = new HSSFWorkbook(fs);

        FileOutputStream fileOut = new FileOutputStream("Some location");

        wb.write(fileOut);


    Strangely, not all characters are altered. For example, the word  
"nebezpecná" becomes "nebezpe?ná" in one cell, but no modification is done to 
the same word in the following cell.

    It appears to come from the way the file is saved to the disk. Maybe POI 
saves the file as an old Excel 95 file, the same problem seems to happen when 
this is done directly in Excel.

    Does anybody know how I can stop these alteration from happening?

    Thanks,

    Alain