Client-side fix:

Tools  >  Internet Options  
>  'Settings' under Temporary Internet files  
>  Select 'Automatically'  >  OK

CSS FIX - Insert in your CSS:

html {
  filter: expression(document.execCommand("BackgroundImageCache", false, true));
}

Javascript FIX:

<script type="text/javascript">
try {
document.execCommand('BackgroundImageCache', false, true);
}
catch(e) {};
</script>