I have two invoices they have the same invoice number, they are for the same part and sales order, but they are for different quatities and shipped on different dates. It seems that when the back order shipped 5/30/07 was invoiced it pushed out the prior invoice shipped 5/22/07. There is no record of the first invoice in the system. How could this of happened?

But it doesn't let us make a new packing slip or invoice without posting the prior invoice. So I don't think that was the problem. We had it happen again. Is there any other reason why this could be occuring.
 
 
 
Thanks