I just switched to Atahualpa and I like the ways to customize it. I just noticed that the category links have an error message:

Fatal error: Call to undefined function the_post_thumbnail() in /home/pennyb46/public_html/jvchdcamcorder.net/wp-content/themes/atahualpa/functions/bfa_post_parts.php on line 124

My site is jvchdcamcorder.net
I spoke to technical support at my host and they said to contact you.

Thanks for any help you can give me!

I'm going to bet you are running WordPress 2.8 or older and have Atahualpa 3.4.5

Please get a fresh copy of Atahualpa from http://wordpress.bytesforall.com/?p=82

There was new code added to support thumbnails, but they don't show up toll WordPress 2.9 and there was a bug in the code. Version 3.4.5.1 fixes this

That was just what the problem was. My categories are working now, and it was a breeze to change over to WP 2.9.1.

Thanks for the awesome support forum and thanks Juggledad for your advice!