Ah! I think I know why. The original kubrick theme uses a repeating image file for the bg. (I had totally forgotten about that). You’ll need to look around the code and delete that particular line. If I remember correctly, all the image code is in the Header file (click on the Header link).
*looking around*
This looks familiar…
/* BEGIN IMAGE CSS */
/*To accomodate differing install paths of WordPress, images are referred only here, and not in the style.css file. If you prefer to use only CSS for colors and what not, then go right ahead and delete the following lines, and the image files. */
body { background: url("<?php bloginfo('stylesheet_directory'); ?>/images/kubrickbgcolor.jpg"); }
#page{ background: url("<?php bloginfo('stylesheet_directory'); ?>/images/kubrickbg.jpg") repeat-y top; border: none; }
#header{ background: url("<?php bloginfo('stylesheet_directory'); ?>/images/kubrickheader.jpg") no-repeat bottom center; }
#footer{ background: url("<?php bloginfo('stylesheet_directory'); ?>/images/kubrickfooter.jpg") no-repeat bottom; border: none;}
I don’t remember whether you’re wanting to mess with the “BODY” or “#PAGE” attributes. In either case, I think you can either (a) yank the image from the images directory or (b) comment the line out. (In my site I just yanked the whole section out, save for the header code. Everything exept the header is CSS. )