Prime size must be multiple of 64, and can only range from 512 to 1024 (inclusive) also with JCE Unlimited Strength Extension

Question

My java software use java 1.6.0_45 and can't upgrade to java 1.7 at the moment, when it try to establish a SSL Connection I got this exception:

Caused by: java.security.InvalidAlgorithmParameterException: Prime size must be multiple of 64, and can only range from 512 to 1024 (inclusive)
    at com.sun.crypto.provider.DHKeyPairGenerator.initialize(DashoA13*..)
    at java.security.KeyPairGenerator$Delegate.initialize(Unknown Source)

I read many posts on internet and stackoverflow, the better suggestion is use JCE Unlimited Strength Extension http://www.oracle.com/technetwork/java/javase/downloads/jce-6-download-429243.html but for me the problem not disappear, I got always the same exception.

I have seen also BouncyCastle's JCE and is working, but I would like to understand because JCE Unlimited Strength Extension is not working.