Wheres my main page image gone

silverstreaks

I've been a happy Smugmug member for about four years and had a virtually trouble free time. For now I'm happy with my current set up and don't have any immediate plans to upgrade
I periodically change the image on my site main opening page a process I have had no problem with until yesterday. Leaving the CSS script as it is all I do is replace the old background image URL with the new and if necessary alter the image size then Press update followed by Submit

Now neither the new or previously listed Images will load and for the life of me I can't fathom out what Ive done wrong. :scratch The below is a copy of the script in question. Hope someone can help

Regards
Bob http://tracksrevisited.smugmug.com/


CSS: #my_banner { display: none;
width: 1250px;
height: 906px;
margin: 0 auto;
background: url(http://tracksrevisited.smugmug.com/photos/i-324KsJq/14/O/i-324KsJq.jpg)
}

.homepage #my_banner {
display: block;
}

#homepage,
#bioBox {
margin: 0 auto;
width: 1250px;
}
#footerLinks {
width: 1200px;
margin: 0 auto;
color: #ccc;
}
#footerLinks a {color: #ccc;}
#footerLinks a:hover {color: #fff;}