css height 100% breaks layout in bootstrap -

why height: 100%; break layout on 1 page, seem required on in bootstrap?

css:

body { height: 100%; }

--

not broken (background spans full page):

http://emailscout.io

--

broken (background stops before end of page):

http://emailscout.io/results/?domain=example.com

html: https://gist.github.com/anonymous/60cdd52499aa6808bf14

if want proper scaled background create new div @ top of page background css want , give height:100%;width:100%;position:fixed;top:0px;left:0px;