Ctrl + F5 - your friend; forces to reload the cold cache. If you are worried that your users have the same problems, however, there is a trick that you can use to get them to get new versions.
Keep in mind that if this is an external resource, you can set the request parameter in the src attribute of the script tag so that IE recognizes it as a different version. eg:
<script type="text/javascript" src="lol.js?new=yes"></script>