Blanks page loads after clicking Confirm Order using CyberSource addon module

Hi, Please help me.
I had same issue for "Blanks page loads after clicking Continue checkout".
I use zencart v1.39h and put a third party addon - cybersource payment gateaway. I understand zencart team not responsible for this.
I try to figure this out for 3 days already,I am exactly follow the addon updater's implement guide line, it just come out the blank page at 2nd step of checkout process when is input mistake. cybersource support team said there is no problem for the setting in their site.
I got blank page after billing information input, and click "Continue checkout", the error message shows on the browser " as :
//gemstone.org/shop/index.php?main_page=checkout_payment&payment_error=cs&error=The+credit+card+number+starting+with++was+not+entered+correctly%2C+or+we+do+not+accept+that+kind+of+card.+Please+try+again+or+use+another+credit+card.&cc_owner=&card_expirationMonth=01&card_expirationYear=10.

with blank page come out!

can anyone help,
you can test at my test account:
user email : ichiu#live.com(# replace with @)
Password : testtest
and you can start from : http://gemstone.org/shop/index.php?main_page=products_all

thanks!

The module needs to be rewritten to use $messageStack for passing errors, instead of passing errors via the URL.

Thans a lot!
So, better I use v1.38 to fit the cybersource addon!
I read from somewhere, someone use v1.38a, and it's working.
I will try it Tonight!
Thanks again

No. v1.3.8a has serious security flaws. Better to use v1.3.9 and fix your addon to work properly.

As a very novice coder where does this change need to be made? I have a client who's bank uses Cybersource as the gateway. I was hoping he had authorize but the bank gave us the great news today that they use cybersource. Any help with how to modify the code and which files would be helpful..