membership + signup password = fatal error

Setup: WordPress multisite ONLY using wpmu plugins using default theme.

1. Network activate the signup password plugin
2. activate the membership plugin on a subdomain site
3. Create your member levels and visit the register page created by memberships
4. click the signup button

The register page will load the form to fill out, however behind the scenes on the server is the error:

[Sun Sep 30 15:35:05 2012] [warn] [client 34.16.34.32] mod_fcgid: stderr: PHP Fatal error:  Call to a member function get_error_message() on a non-object in /home/website.net/public_html/wp-content/plugins/signup-password/signup-password.php on line 192, referer: http://website.net/register/

The only reason this doesn't really effect the user and probably isn't widely reported is because this error happens in the split second between the 'sign-up' button being pressed and the register form loading.

It is still a huge error though.

also:
There is a general error message every time you simply load the /register/ page created by memberships

mod_fcgid: stderr: PHP Warning:  Cannot modify header information - headers already sent by (output started at /home/mysite.net/public_html/wp-includes/post-template.php:168) in /home/mysite.net/public_html/wp-includes/pluggable.php on line 876, referer: http://subdomain.mysite.net/wp-admin/edit.php?post_type=page
mod_fcgid: stderr: PHP Warning:  Cannot modify header information - headers already sent by (output started at /home/mysite.net/public_html/wp-includes/general-template.php:169) in /home/mysite.net/public_html/wp-includes/pluggable.php on line 876, referer: http://mysite.net/register/