in your 'Body Style' options you have
HTML Code:
body{
text-align:center;
margin:0;
padding:0;
font-family:tahoma,arial,sans-serif;
font-size:0.8em;
background:#000000;url(/demo/atec/wp-content/themes/atahualpa/images/bg2.jpg) no-repeat top left;
padding-top:20px;
padding-bottom:20px
change the ';' after #000000' to a space.
the ';' defines the end of the option, so while the color is applied to the background, the url for the image is ignored. (damn punctuation

)