GM,
You need to fix the thread title and never post an entire file when a snippet will do. Sorry if I sounded harsh before, but you've been around for awhile now. We expect more from you.
Copy my tab code exactly as I have it in my example.
Just change what you absolutely need, don't try to get too fancy. You need to flush your template cache either from the Summery page in the admin or via
http://www.yoursite.com/xcartdirectory/cleanup.php.
Just try and get a basic mouseover (hover) change happening before trying to butcher all of the code. Your idea of moving it up the Style Sheet doesn't have any effect.
This is a rudimentary error, but we need to know that you are trying the basics first. Always make troubleshooting simple.