Probably related to:
#015451: SQL query error from eZArchive when accessing "extra info" on webin blogs.

With mysql in strict mode you'll get the following sql error:

Fatal error: mysql_query(): Query error (1055): 'trunk.ezcontentobject_attribute.data_int' isn't in GROUP BY. Query: SELECT MONTH( FROM_UNIXTIME( ezcontentobject_attribute.data_int ) ) AS month, YEAR( FROM_UNIXTIME( ezcontentobject_attribute.data_int ) ) AS year, UNIX_TIMESTAMP( CONCAT( YEAR( FROM_UNIXTIME( ezcontentobject_attribute.data_int ) ) , '', MONTH( FROM_UNIXTIME( ezcontentobject_attribute.data_int ) ) , '', 01 ) ) AS timestamp FROM ezcontentobject_attribute, ezcontentclass, ezcontentclass_attribute, ezcontentobject_tree WHERE ezcontentclass_attribute.contentclass_id = ezcontentclass.id AND ezcontentclass.identifier = 'blog_post' AND ezcontentclass_attribute.id = ezcontentobject_attribute.con in /home/andre/workspace/trunk/lib/ezdb/classes/ezmysqlidb.php on line