Hi Jan,
I found the JoomSEF metabot and saw that the settings are correct. I have no other SEF component installed. The only one I could find is the system one. I deactivated that in the plugin manager to no effect, but did not uninstall it because it came with Joomla and I was afraid that might break something.
We are using a Rockettheme template with no custom modifications. This site is as simple as they come. Very few if any extensions installed. They are in Joomla 1.5.7
www.tfmattorneys.com/
I've used Artio on another Rockettheme site with no problems. This site is a very complex site with many extensions installed. There were some conflicts, but I turned those extensions off in the JoomSEF config. They are in Joomla 1.5.4. Legacy mode. Works fine here but not in the site in question.