Way to go. I'm in the process of converting from table to a pure CSS layout. Ugh, the data transfer is time-consuming, but CSS is oh-so-more flexible.
I think I see your problem. From your Benifits of Nuclear page:
The way CSS works is that the last line read takes precedence. Therefore, since the Geocities CSS file loads up last, it rules.
<title>Freedom For Fission- the benefits of nuclear</title>
<LINK REL=STYLESHEET HREF="../fissionstyles.css" TYPE="text/css">
<!-- following code added by server. PLEASE REMOVE -->
<!-- preceding code added by server. PLEASE REMOVE -->
Beat them at their own game. Put your CSS link (<LINK REL=STYLESHEET HREF="../fissionstyles.css" TYPE="text/css">) in the next line down.
Now you're suppose to put the CSS links in the head and this'll move it to the body, but... that's where they went. Just make sure you put it in before any layout or text code.