I am having this problem too since upgrading to 2.6 – when you click to leave a comment, it gives an error message, such as this. (hope that link works) I would REALLY appreciate help on this comments issue – this has never happened before with an upgrade (though other problems have). It’s not a membership issue and it’s not a theme issue, because I switched back to the WP default and it has the same problem. thanks for any help.