Background image

Hi, not sure if i'm missing something here, if its a bug or if its not available. I want to add a repeating background texture to fill a page but I can't get it to show up. This is what I do: in the page options click the + symbol in general > HTML Body background and add my repeating image and change the relevant repeat/background size options. The background image doesn't show, it works if I change it to a colour so not sure why a background image won't show.
Can you let me know if it should work or if a background image can't be added.
Thanks
Karl