UPDATE: Layout issues aside, I think this is your primary problem:
GET http://www.securemycargo.com/.../nivo-slider.css 404 (Not Found)
CSS is a critical part of such a utility. Without it, overflow isn't controlled and images aren't sized properly. I've placed the file at http://dq3f8u841c3z3.cloudfront.net/wp-content/plugins/nivo-slider/scripts/nivo-slider/nivo-slider.css in your page via dev tools and it solves your issue.
At least part of the problem is that you're using tables for layout, and the table isn't wide enough. The images aren't shown on load, so the browser makes it too narrow. At a minimum, set the width of the table to 100% to let it use the entire main column:
<table width="100%">
<tr>...
Note that the width attribute is deprecated. If you're using tables for layout, though, you probably don't much care. If you happen to care, use CSS instead:
<table class="main-col">
<tr>...
<style>
.main-col {width: 100%;}
</style>
Better: remove that table altogether. Tables are for data, and this one has just one cell in it anyway.