I've been getting this error today when I try and post in this forum.
The message still posts, but you don't realize it until you refresh the page.
I see that others have double posted as well and I'm guessing it's because of the same reason.

Is everyone having this problem?

Gdn_ErrorException thrown within the exception handler.
Message: Cannot modify header information - headers already sent by (output started at /home/slitaz/www/forum/library/core/class.email.php:113) in /home/slitaz/www/forum/library/core/functions.error.php on line 62