OK, if you are using Internet Explorer, here is how you get StatTracker to work. (in Internet Explorer 6):
In IE, go to Tools-Internet Options-Advanced tab. Scroll down to around the middle of the advanced list, and you should see two subsections, one for Java (Sun), and one for Microsoft VM. Under Java (Sun), uncheck the "use java 2v....." checkbox, and in the Microsoft VM section, check the Java console enabled checkbox. Reboot, and StatTracker should then work.
If the Microsoft VM section is not there, you only have Sun Java installed, and not Microsoft Java. Unfortunately, MS doesn't provide their Java VM for download anymore because of a lawsuit mess, but I found an external link where you can download it. Just use any of the download links in the top section of this page, and you can install MS Java, and StatTracker should then work. (the first link doesn't work, but the second one does.)