I’ve got the exact same error message when I switched to the famous soleil theme by Avi Alkaley. I use this theme with the WP 2.x Version before with no problems.
I deactivated all plugins with no effort. Couldn’t do anything.
BUT: When I switched to the WP 2.2 default theme and activate all my plug-ins again everythings is fine again.
Finally, if I then activate the soleil theme, I’ve got the same error message again.
(MySQL 4.0 / PHP 5.0 / WP 2.2).