WordPress MU

When I choose a different Admin Bar theme and click Save Changes on the Admin Bar settings page, I get:

Warning: Invalid argument supplied for foreach() in /.../html/wp-admin/includes/plugin.php on line 626

Warning: Cannot modify header information - headers already sent by (output started at /.../html/wp-admin/includes/plugin.php:626) in /.../html/wp-includes/pluggable.php on line 856

However, when I go Back from the error page and the Admin Bar settings page reloads, the Admin Bar theme hasn't changed - the colors are the same - but the new theme is now the chosen one in the Theme drop down, as if my new choice was stored in the db but not actually applied.

Anyone else seeing this?

Nudge

Do you have any plugins enabled?

Yep, that was it. A conflict with:

http://planetozh.com/blog/my-projects/wordpress-admin-menu-drop-down-css/

Which, I just learned, also allows you to change its theme color, while still working better than the default Admin Bar.

thanks!