I upgraded to 1.8.1 on WP 3.0.2 and realized it wasn't working. Error log gave me ...
WordPress database error Unknown column 'url_wpid' in 'field list' for query INSERT INTO wp_wassup_tmp (wassup_id,timestamp,ip,hostname,urlrequested,agent,referrer,search,searchpage,searchengine,os,browser,language,screen_res,spider,feed,username,comment_author,spam,url_wpid) ...
I uninstalled, deleted, and reinstalled. It's back to normal.