Error reading the excel file

Hi ,

I am having some problem when reading the excel file.

While reading excel file I am getting error-*java.io.IException:
*Unable to read entire block; 4 bytes read; expected 512 bytes.

InputStream stream = objFormFile.getInputStream();

PIFSFileSystem fs = new PIFSFileSystem(stream); above error here.

HSSFWorkbook wb = new HSSFWorkbook(fs);



Case 1:

I download the file on the system ,save it ,and then directly upload it to
the system ,I get the above error .



Case 2:

It works fine if I download the excel and manually open and save it and then
upload it .

I am using JDK1.4.1,poi-2.5.1-final-20040804.jar.

Can u please help me out for the above problem?