AbleCommerce Shopping Cart Software

Very odd. My production web site just produced an order as if it was running in "demo" mode; Order and OrderShipment address information overwritten with "DEMO" in every field.
Fortunately, anonymous customer address info was preserved in ac_Addresses.
No errors in Able logs, web server event logs. Somewhat troubling - any guesses as to cause?

Can you confirm that the store has not been set to run in demo mode? Check under Configure -> Security -> Licensing.

Unless done without my knowledge (unlikely but possible, I guess), no - and would have had to be changed back as well.
Is there any audit for that?
First thing I did was quickly check the ablecommerce.config file.
Then I followed the same path through the site as the user did for the DEMO order, except I used a coupon for payment instead of a credit card. My order was correct (phew).
After that, I dug out the correct address info and manually updated the order and order shipment records, and resent order confirmation email (after adding a note) to the site user.
Hasn't happened since.

Eeek! This happened again. Any way to trace what might be contributing to this problem? What might cause this? There is no way that DEMO mode was on at the time.

Ok - this gets a little weirder.
Now I have an order that has correct address info in ac_Orders, but DEMO info in ac_OrderShipments.
We've recently done substantial refactoring of the Able UI (converted to web project), so I suspect that is of some influence here.
Please, please - what is the logic for address info getting replaced in orders?

And another DEMO order.
We also use multiple domains (3) in our license - could that be a factor?