Errors After Upgrade to 2.6

I’m getting following errors after upgrade to WP Version 2.6 from 2.5.

When I try to make a post.
Cannot modify header information - headers already sent by (output started at /mnt/w0807/d41/s24/b02e1c06/www/domain.com/wp-content/plugins/yet-another-photoblog/Yapb.php:99) in /mnt/w0807/d41/s24/b02e1c06/www/domain.com/wp-includes/classes.php on line 806

When I try to enable a plugin.
Warning: Cannot modify header information - headers already sent by (output started at /mnt/w0807/d41/s24/b02e1c06/www/domain.com/wp-content/plugins/yet-another-photoblog/Yapb.php:99) in /mnt/w0807/d41/s24/b02e1c06/www/domain.com/wp-includes/pluggable.php on line 770

It looks the plugin yet-another-photoblog is creating problems, so i disabled it and now it gives our this error.

Warning: Cannot modify header information - error in /mnt/w0807/d41/s24/b02e1c06/www/domain.com/wp-includes/pluggable.php on line 770