Mailhandler dishes out a flurry of errors on retrieve

* warning: Invalid argument supplied for foreach() in /modules/node/node.module on line 561.
* warning: implode() [function.implode]: Invalid arguments passed in /modules/node/node.module on line 565.
* user warning: 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.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 /includes/database.mysql.inc on line 174.
* warning: Invalid argument supplied for foreach() in/modules/node/node.module on line 561.
* warning: implode() [function.implode]: Invalid arguments passed in /modules/node/node.module on line 565.
* user warning: 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.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 /includes/database.mysql.inc on line 174.
* warning: Invalid argument supplied for foreach() in /modules/node/node.module on line 561.
* warning: implode() [function.implode]: Invalid arguments passed in /modules/node/node.module on line 565.
* user warning: 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.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 /includes/database.mysql.inc on line 174.
* warning: Invalid argument supplied for foreach() in /modules/node/node.module on line 561.
* warning: implode() [function.implode]: Invalid arguments passed in /modules/node/node.module on line 565.
* user warning: 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.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 /includes/database.mysql.inc on line 174.

The retrieve itself works fine, but the comment never gets posted. What could be wrong?