looking back at the default power store designs, there is not suppose to be a separator between the news items.
you can add one if you like by adding a border-bottom attribute to the #contentWrapper .sidebar .news ul selector in the webassist/themes/GBTS/css/default_styles.css file:
#contentWrapper .sidebar .news ul {
border-bottom: 1px solid #000000;
list-style: none outside none;
}
I dont see any issues testing your page in IE7 or IE8, please be more specific, I will also need more specific details on what problems you are having with "some images"