I've read the long 163 pages and I saw some people with the same problem as I have.
But no solution.
I installed the latest version and all is working. Great contrib.
But the only thing not working is mailing the pdf.
When I changed my order and click on the 'new order email' button nothing happens.
No mails being send.
I have InvoicePDF 1.62
Hope someone can help me out.