Product Options not appearing on invoice or database

As per the title. Using 1.5.2.1

The same customer has just ordered the same products (9 mins apart - I guess they just ordered too few first time round).

The 1st order displayed:
- the product options on the email invoice.
- the product options on the Sales > Orders > Products in Admin.
- the product options on the database under order_option.

The 2nd order displayed:
- just the product name and id but none on the Product Options on the email invoice
- just the product name and id in Sales > Orders > Products in Admin.
- zero data at all in the DB under order_option ?!!?

How on earth can the system suddenly miss off this information? It's worrying to say the least as now my client has to phone the customer and ask them what they ordered.

Has anyone encountered this, or can anyone offer an explanation as to why it may happen??

I've searched and searched but the only incidents of this happening relate to version 1.4.x not my version.

The simplest explanation is the product option wasn't set as required so the customer simply added to the cart without it. I'd start by checking there and then look at more complicated possibilities.

I should have mentioned that the options are all set to required so a customer can't add to cart without choosing an option first.

It happened again yesterday on two orders.

I'm desperate to find an answer on this!

Then you have more complex issues. Did you remove an option value from the product recently? This will cause the issue with saved carts, even if you went back later to the product and re-added the same option value.

No, haven't done any removals of any of the options.

I've done some more digging and have increased the memory size on the php.ini files in Admin and Root, as some threads point to this being a possible culprit.

I will report back.

Look in order_option and confirm the product_option_id and product_option_value_id still exist in product_option and product_option_value.