File transfer error

I have created an application for receiving and sending fies. I am basically using the following code to uplaod a file:

// Create the file transfer manager

FileTransferManager manager = new FileTransferManager(connection);

// Create the outgoing file transfer

OutgoingFileTransfer transfer = manager.createOutgoingFileTransfer("romeo@montague.net");

// Send the file

transfer.sendFile(new File(“shakespeare_complete_works.txt”), “You won’t believe this!”)

the upload starts and after the “negotiating transfer” status an “error” status is received and the upload is stopped. FYI From another application (“Gajim”) im able to receive files with ease.