Ok. To resume:
The freeware version worked fine. I deleted it after having problems w/ upgrading.

This is a fresh install of 5.47.
My control panel url is http://www.scattergirl.com/ubb/cp.html

I'm getting "File Not Found" errors on everything. My cplinks.html file has been edited with the correct path:
<BASE HREF="http://www.scattergirl.com/cgi-bin/">

There really is a directory called cgi-bin in my htdocs (which also include the directory ubb), so I don't understand why none of the scripts are being found.

Help. Please. This is so Murphy's Law I'm tearing my hair out. Thanks.

Ok fixed it.

The problem was that I followed the directions , which said to name the cgi directory "cgi-bin". On my server, scripts can run from anywhere, except cgi-bin, which is reserved. Changed the name to something else, fixed the cplinks.html path, and voila.

Phew.