How are you linking your CSS? Is it inside or external? I know you have to have a very specific setup for loading the themes properly. The call has to look like this:
PHP Code:
<link rel="stylesheet" href="templates/simple/inc/style.css" type="text/css">
or it won't work.
If you want I can see about a simple and efficient sci-fi/computer theme today, I have time after all. :)