When the "Input Filter" field is hidden and I try creating a node or editing one I get the form error:
Illegal choice <p><a href="/filter/tips">More information about formatting options</a></p> in Input format element.

I tried changing the field weight to something other than "unset" as it has no "Original Weight" defined, but then I get this php error:
SMTP Error: Data not accepted.
which when looking at the logs shows as:
Cannot modify header information - headers already sent by (output started at /my_install_directory/sites/all/modules/messaging/messaging_phpmailer/PHPMailer/class.phpmailer.php:522) in /my_install_directory/includes/common.inc on line 319.

When the field is not hidden everything works just fine.