error on saving settings

hi, have just installed custompress to work alongside Directory and am getting this error when trying to save the settings for the first time.

Warning: Illegal offset type in isset or empty in /home/bartaclu/public_html/wp-includes/post.php on line 828
Warning: Illegal offset type in isset or empty in /home/bartaclu/public_html/wp-includes/post.php on line 828