Java EE (Java Enterprise Edition) General Discussion

I have written a little servlet that uploads files from the client to the server, using FileUploader of Jakarta. This servlet works fine on the WSAD but when I tries to run it using Websphere I get the following exception:

FileUploadException Processing of multipart/form-data request failed. No such path or directory. /temp/upload_00000013.tmp

The relevant code is:

DiskFileUpload fu = new DiskFileUpload();
fu.setSizeMax(1000000);
fu.setSizeThreshold(4096);
fu.setRepositoryPath("/temp");
List fileItems = fu.parseRequest(req);

The structure of the war file is:
WEB-INF
/classes
/temp
/lib
/temp

The directory exists, so where am I wrong?