Some sales completing without required attribute

[djtrillian]

We have a few items where an attribute MUST be chosen in order to add to the cart and checkout, there is no way I have ever found to trick the cart into adding an item without choosing a required attribute.

Yet somehow we get, at random, an order now and then where no attribute is specified and we have to contact the customer to find out what they ordered etc.

If I had any theory as to how this might happen I could look for ways to prevent it.

A prime example would be here: http://www.credenceonline.co.uk/zen/...roducts_id=310

It's a ticket for an event but they must specify the date / venue, no way to add to cart without the attribute and yet just today we received an order for two tickets with no attribute specifying the date / venue

How can this happen? What is the most likely cause?

[lhungil]

Do you delete / add attributes to products? How long ago were the customer accounts created (where the products w/o required attributes were purchased)?