Warning: array_merge() – wp-includes/widgets.php on line 53

I recently updated to wordpress v2.5.1 and I get the following error when trying to login admin.

Warning: array_merge() [function.array-merge]: Argument #2 is not an array in /home/hustler/public_html/jacquescousto/wp-includes/widgets.php on line 53

Warning: Cannot modify header information – headers already sent by (output started at /home/hustler/public_html/jacquescousto/wp-includes/widgets.php:53) in /home/hustler/public_html/jacquescousto/wp-includes/pluggable.php on line 390

Also, I get this error on the top of every front end page:

Warning: array_merge() [function.array-merge]: Argument #2 is not an array in /home/hustler/public_html/jacquescousto/wp-includes/widgets.php on line 53