CSS3 gradient background set on body doesn’t stretch but instead repeats?

Apply the following CSS:

html {
    height: 100%;
}
body {
    height: 100%;
    margin: 0;
    background-repeat: no-repeat;
    background-attachment: fixed;
}

Edit: Added margin: 0; to body declaration per comments (Martin).

Edit: Added background-attachment: fixed; to body declaration per comments (Johe Green).