java.lang.NoClassDefFoundError: javax/crypto/NoSuchPaddingExcepti on

[Khalid Ishaque]

When I use JDK1.4 every thing works fine, but the second I switch to JDK
1.3.1, I get the java.lang.NoClassDefFoundError:
javax/crypto/NoSuchPaddingException error.  Any suggestions???
 
Thanks
 
--Khalid