Unable to process credit card order

I am receiving a message after the check out is pressed that the order information order cannot be processed Because the credit card information is incorrect. This has happened after taking the store out of test mode for authorize.net , In fact the page actually hangs while it's trying to process. I know there are many Posts with regard to this but have not found a solution.

So far support has been great in solving the other issues I've had And I'm hoping this is no different. The website is store

I am at the point now where the customer is actually losing money because of the little issues that we have run into.

Help in solving this issue so that the store can come online would be great. I have tried using the full message code in the check out _ failure page That as I said the pages hanging and doesn't get that far.

Thanks