background-image disappearing after load

hello

i added an background-image to my wordpress website

but when i open the website, my background only appears about 2 seconds – the time to load the page, then disappears and the background turn white

heres my page http://www.connectto.com.br/websites/

i added the code above to style.css

body {
background: #e2e2e2;
background: url(images/bg-connectto.jpg) no-repeat center center fixed;
-webkit-background-size: cover;
-moz-background-size: cover;
-o-background-size: cover;
background-size: cover;
}

im doing my updates in a copy of tewntyeleven

anyone can help please, need to know why this background-image keeps disapearing

thanx,