the problem is in your style.css
do not give background image to the first tag (delete the background parameter there...
/* Global reset by Eric Meyer */
html, body, div, span, applet, object, iframe,h1, h2, h3, h4, h5, h6, p, blockquote, pre,a, abbr, acronym, address, big, cite, code,del, dfn, em, font, img, ins, kbd, q, s, samp,small, strike, strong, sub, sup, tt, var,b, u, i, center,dl, dt, dd, ol, ul, li,fieldset, form, label, legend,table, caption, tbody, tfoot, thead, tr, th, td {margin: 0;padding: 0;border: 0;outline: 0;font-size: 100%;vertical-align: baseline;background:url(
http://www.kleinkindreiten.de/Mirror%20pony%20faded.png);}to
/* Global reset by Eric Meyer */
html, body, div, span, applet, object, iframe,h1, h2, h3, h4, h5, h6, p, blockquote, pre,a, abbr, acronym, address, big, cite, code,del, dfn, em, font, img, ins, kbd, q, s, samp,small, strike, strong, sub, sup, tt, var,b, u, i, center,dl, dt, dd, ol, ul, li,fieldset, form, label, legend,table, caption, tbody, tfoot, thead, tr, th, td {margin: 0;padding: 0;border: 0;outline: 0;font-size: 100%;vertical-align: baseline;}
and modify the next "body" tag here:
/* -- GLOBAL STYLES --------------------------------------- */
body { line-height:1; color:#333; font: 12px Arial, Helvetica, Verdana, sans-serif; }
to:
/* -- GLOBAL STYLES --------------------------------------- */
body { line-height:1; color:#333; font: 12px Arial, Helvetica, Verdana, sans-serif; background:url(
http://www.kleinkindreiten.de/Mirror%20pony%20faded.png);}done.