Blank invoice using HSBC module

[Blaze Falconburger]

About 1/3 of our invoices are blank (see attachment).
The recover cart module allows us to see what the customer has in their cart, but sometimes their orders come through blank in the admin.

The other 2/3 come through just fine, there is nothing in common that I have found so far between the orders. Can anyone shed any light?

We are using the HSBC module. This modifies slightly process checkout - creating the order ID before passing to HSBC's site. But it always returns OK and gets as far as writing the order ID to the table but not items! (This routine is left as original).