[Plugin: Quotes Collection] : Not Working in 3.0.1 (Multisite)

I’m trying to add the Quotes Collection widget to a site on our blogging system (running 3.0.1 with multisite turned on).

The first quote shows up fine. However, for the second quote when I click to the next quote or turn on the automatic rotation of quotes, I get the following error message:

Fatal error: Cannot redeclare class wpdb in /home/umwblogs/public_html/wp-includes/wp-db.php on line 53

Any thoughts what this could be?