[wp-testers] 2.5 upgrade error- coding?

[CoralPost]

hello

Just upgraded to 2.5.  Nice BTW but, I am receiving this error at the top of each post:

"Warning: array_key_exists() [function.array-key-exists]: The first argument should be either a string or an integer in /home/myfault/public_html/wp-includes/category-template.php on line 192"

This would seem to suggest a coding error, but I am not a PHP guru.  

While this appears at the top of each post, clicking on that post displays properly and all else seems to be working fine.

Ideas?  Assistance?

The site is: www.hisfault.com

-- 
Best regards,
 CoralPost                          mailto:tl at coralpost.net