With certain valid settings, Atahualpa's page menus are rendered incorrectly in IE7.
The site below was setup to demonstrate the issue. It is running a default installation of WordPress 2.7.1 and Atahualpa 3.3.3. The only configuration changes made are shown in a screenshot on the home page. A screenshot of the menus rendered by IE7 is included. I also included a screenshot showing more severe corruption at my live site.
For those not wishing to visit the site, the screenshots are attached.