Since then I;ve tried everything I can think of to troubleshoot the problem. I can create new invoices for old clients but not for any new ones. I can create invoices for the new clients and print them from the screen, but since I can't save them, it's useless for tracking and audit purposes.
I have exported the customer list and examined it for anything that looked odd and can't find anything. I have entered the new customer from the address book first before invoicing them, and although the address comes up correctly, it still won't save the invoice.
I have validated the file with no obvious errors. I have very a small address book and even smaller number of customers. Has anyone ever encounterd this oddity or have any suggestions for what else I can try to eliminate or work around it?