Root container background image not showing

Is there any known problem with adding a background image to the root of a Flex view?

  • I've uploaded the png image and copied the path from the Image Management tool and prefixed it with /system/images/. It doesn't display in Designer or in the browser.
  • I've repeated the exercise using the Image component and dropping the same path into the source and it works.
  • I've tried setting the background image in a FlexContainer and it doesn't work.

Am I missing something?

It seems that syntax is,
backgroundImage : url(/system/images/pathToMyImage.png)