Transaction not going through - AuthNet Module

[olivus]

Hi Zen Community,

I received an email from a customer:

> Your site will not let me order. Each time I submit the order, it clears the
> Credit Card and displays a red line at the top saying to input the credit
> card information. This happened when I ordered a month ago also. There is
> nothing wrong with my credit card, I just made another purchase with it -
> and there was nothing wrong last month either. I am afraid I cannot do
> business with you if your site will not take my credit card.

We have no processing issues (we know of) and have been receiving orders, which are processed via authorize.net. We are using ZC v1.3.8a

Any ideas as to what is causing this?

[Kim]

What browser is the customer using?

[olivus]

Customer is using IE7.