Java Security

Hi!

I have an exception when I am decrypting a SealedObject:

javax.crypto.BadPaddingException: Given final block not properly padded

I encrypt my SealedObject using a DES key. This key is saved as a variable and passed to the decryption method and used to decrypt the SealedObject. This is the code for it

desKey = keyGen.generateKey();

public Vote decryptVote(SealedObject so, desKey)
{
Cipher decipher;
Vote vote = null;
try {
   decipher = Cipher.getInstance("DES");
   decipher.init(Cipher.DECRYPT_MODE, desKey);
   vote = (Vote) so.getObject(decipher);
} catch (NoSuchPaddingException e) {
  System.out.println("");
  e.printStackTrace();

I have used my IDE debugger and looked at my code and I can see that the data in my Key is the dame at encryption time and deryption time.
I am new to cryptography and I would be grateful tp even find out what a Bad Padding exception is!

Thanks for your help,

Chris