Visual Editor Background Image - Does Not Display Full Image

When using the Visual Editor to define a background color and image in Backgrounds > General it generates CSS code as below below with Color defined properly in the BODY tag but the background Image defined in HELPER-CONTAINER class.

[color=#000000]End result - if your page doesn't fill the browser viewport vertically then neither does your background image and there is a hard cut off and shift to the background color. It doesn't matter if the image is tall enough or set to repeat because the background only fills the container that wraps around the content of the page. [/color]

[color=#000000]Why wouldn't the site background image be in the Body tag as a true background image should be? Is this a bug or perhaps by design? [/color][color=#000000]How best to address this issue and have a true background image? [/color]

body {
background: #ffffff;

.helper-container {
background: url('../../../../../../../../design/themes/mytheme/media/images/patterns/Satori/
1409010983?1409011327?1409011335?1409011355') top left repeat fixed;


Removed the background image and added custom CSS in the Visual Editor redefining the BODY tag, worked perfectly so short height pages actually have a full background on 900px or taller display ports (pages like compare list, reset password, custom pages etc)