Crystal - Background Image

I have create an invoice style report which I want to place a background image across the page.

In 'page header a' I placed the image and ticked 'underlay following sections'.

My problem is that the image will not print into the page footer as it states the page header + page footer is too big for the page.

I need to print the page footer as this is where the totals print for the invoice.

If appears the page header will not overlay into the page footer. Is there a setting I am missing?