PDOException when uninstalling module

I get the below PDOException when trying to uninstall the user module on a Drupal 7 RC3 site:

PDOException: SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''xmlsitemap_settings_user_%%' at line 1: DELETE FROM {variable} WHERE name LIKE 'xmlsitemap_settings_user_%%; Array ( ) in xmlsitemap_user_uninstall() (line 36 of [path]\sites\all\modules\xmlsitemap\xmlsitemap_user\xmlsitemap_user.install).