get the following in cron()

Fetching external blog entries...!!! Comparisons of text column conditions are not allowed. Please use sql_compare_text() in your query. !!!
!! Stack trace: * line 513 of /lib/dml/moodle_database.php: dml_exception thrown

• line 1574 of /lib/dml/moodle_database.php: call to moodle_database->where_clause()
• line 238 of /blog/lib.php: call to moodle_database->delete_records()
• line 162 of /blog/lib.php: call to blog_delete_external_entries()
• line 458 of /lib/cronlib.php: call to blog_sync_external_entries()
• line 79 of /admin/cron.php: call to cron_run()
  !!