Suddenly Adding past order totals to purchase?

Hey guys,

First, I know this cart is not the current one, however it has worked fine up until yesterday when a client tried to order a product and apparently the cart also added all her previous purchase totals to her purchase.

The cart users office person then went to place a test order and apparently it did the same to him. Two orders so far. Here is the actualy comment of the customer...

"Every time I try to order off website, I have problems. This time,
Shopping Cart is trying to charge me for reports I purchased in 2009 plus the new reports I want for 2010. It is trying to charge me for 11 reports when I'm only wanting 4."

The version is 1.3.5 (4 years old). Any information would be deeply appreciated.

Thanks,
Mark

She may have bookmarked the site with a previous ZEN-ID code.

This could result in the session being recalled and previous cart items added in.

Ask her what URL she used to access the site.

If it looked something like this: