One thing that may work better is to use the same protocol as the page the status image is being displayed on.
Code:
<script type="javascript" src="//www.yourdomain.com/phplive/js/status_image.php?base_url=//www.yourdomain.com/phplive&l=admin&x=1&deptid=0&"></script>
Note: Instead of specifying "http:" or "https:" your browser should assume whatever protocol is being used by the current page. This should supress the "unsecure items" warning in IE.
Keep in mind if SSL is not properly configured on the server you host PHPLive on, trying to show it using "https:" will most assuredly fail.
The mod also assumes you are familiar with the deployment and configuration of PHPLive (we used "owned" instead of "hosted").