Background disappearing

Background disappearing

Hello, i'm building a site that needs a full page background, so I've used this code in the stylesheet.css

html {
/*Código para fazer background full screen*/
background: url( http://imageshack.com/a/img593/4093/dej6.jpg) no-repeat center center fixed;  
  -webkit-background-size: cover;
  -moz-background-size: cover;
  -o-background-size: cover; 
  background-size: cover;
}


It was working well until i referenced the jquery mobile css, but now it doesn't appear on the background and neither one bar that i've created in the stylesheet.

When I comment the jquery mobile css, the background appears.

<meta name="viewport" content="width=device-width, initial-scale=1"><!-- Coloca a tela do tamanho da tela do dispositivo-->   
<!-- <link rel="stylesheet" href="http://code.jquery.com/mobile/git/jquery.mobile-git.min.css"> -->
<link rel="stylesheet" href="stylesheet.css" /> <!-- Our Stylesheet -->
<script src="http://code.jquery.com/jquery-1.10.2.min.js"></script>
  <script src="http://code.jquery.com/mobile/git/jquery.mobile-git.min.js"></script>
</head>