till there’s an official fix, change this in googleanalytics.php:
if ( !isset( $ga_admin ) )
$ga_admin = new GA_Admin();
$ga_admin->set_defaults();
to this:
if ( !isset($ga_admin) && class_exists('GA_Admin') )
$ga_admin = new GA_Admin();
if ($ga_admin) $ga_admin->set_defaults();