Error when using the 'Vote' button to vote at a poll

Warning: Invalid argument supplied for foreach() in /home/sempre/public_html/v4/modules/node.module on line 363

Warning: implode(): Bad arguments. in /home/sempre/public_html/v4/modules/node.module on line 366

Fatal error: 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 '' at line 1 query: SELECT n.nid, n.vid, n.type, n.status, n.created, n.changed, n.comment, n.promote, n.moderate, n.sticky, r.timestamp AS revision_timestamp, r.title, r.body, r.teaser, r.log, r.format, u.uid, u.name, u.picture, u.data FROM node n INNER JOIN users u ON u.uid = n.uid INNER JOIN node_revisions r ON r.vid = n.vid WHERE in /home/sempre/public_html/v4/includes/database.mysql.inc on line 108