Hi All
Thanks for your response. We have"Direct Invoice Printing" turned on so invoices are printed as soon as orders are posted.

We have 3 persons running OE at the same time, processing orders, printing invoices, and credit notes.

There were no error messages. In the first instance, it was brought to our attention by a customer a month later.

Yes, we use "suppress zero qty on invoices" but the items all had quantities shipped.
Our invoice specification has 1 copy since we use a dot matrix printer (invoices are corbonized)

Ruth