PHP error

PicLens displays the link "Start slideshow erroneously on a page where no photos exist and when clicked the following PHP errors occur :

Type php
Date Friday, June 6, 2008 - 17:04
User admin
Location http://www.xxx.com/piclens/piclens_acidfree/
Referrer http://www.xxx.com/admin/logs/event/10928
Message Invalid argument supplied for foreach() in modules/node/node.module on line 521.
Severity error
Hostname xxx

Type php
Date Friday, June 6, 2008 - 17:04
User admin
Location http://www.xxx.com/piclens/piclens_acidfree/
Referrer http://www.xxx.com/admin/logs/event/10928
Message implode() [function.implode]: Invalid arguments passed in modules/node/node.module on line 525.
Severity error
Hostname xxx

Type php
Date Friday, June 6, 2008 - 17:04
User admin
Location http://www.xxx.com/piclens/piclens_acidfree/
Referrer http://www.xxx.com/admin/logs/event/10928
Message 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 172.
Severity error
Hostname xxx