Warning messages when processing feed


I configured Autoblog to fetch posts from my global network. Running "Process" Feed gives warnings:

Warning: mysql_real_escape_string() expects parameter 1 to be string, object given in /wp-includes/wp-db.php on line 789

Warning: Cannot modify header information - headers already sent by (output started at /wp-includes/wp-db.php:789) in /wp-includes/pluggable.php on line 881

What could it be? I use feed from Global Recent Posts Feed.

Best regards,