I have created a custom theme for my invoices. On screen it shows perfectly, but when I save it to pdf or when I print it, it reverts to the old theme.
what do you mean by this? it reverts to the default in-built themes or your previous custom theme?
you should understand that not all codes work with the internal pdf generator. it would only display correctly in Manager because the program basically works like a browser. the pdf generation is completely different process.
maybe a few screenshots would help understand your problem better.
Here is the screenshot from the invoice showed in Manager, the second is the screenshot of the pdf generated.
You are responsible for the performance of your own custom themes. There is apparently something in your coding that is preventing conversion of your footer information in the PDF. I would begin by eliminating the background shading. Always remember that Manager is not what you see is what you get program.