Exception : Extern sheet is part of LinkTable

[Remi Moretti]

Hello,
I am using the library to develop a tool that is used to parse and work on 
excel files generated by an external tool.

I am having this problem when trying to open any of those excel file :
Exception in thread "main" java.lang.RuntimeException: Extern sheet is 
part of LinkTable
        at org.apache.poi.hssf.model.Workbook.createWorkbook(
Workbook.java:192)
        at org.apache.poi.hssf.usermodel.HSSFWorkbook.<init>(
HSSFWorkbook.java:248)
        at org.apache.poi.hssf.usermodel.HSSFWorkbook.<init>(
HSSFWorkbook.java:169)
        at org.apache.poi.hssf.usermodel.HSSFWorkbook.<init>(
HSSFWorkbook.java:151)
        at PTRRF.<init>(PTRRF.java:58)
        ...
Here is the code that fails:

    public PTRRF(String file) throws IOException{
        filename = file;
        fs = new POIFSFileSystem(new FileInputStream(filename));
        wb = new HSSFWorkbook(fs); //fails here
    }

The library however opens correctly a file that I create using MSExcel. I 
guess it means that the generated file I use is malformed.

This problem occurs with POI3.1FINAL.

Could you help me on this problem ? What is malformed in the file I use ?
Don't hesitate to ask me for more details (including a generated excel 
file maybe) !
Thank you for your answers.
Remi