[Plugin: MailPress] undefined method MP_User::get_id()

I am receiving a couple errors from mailpress the first is when i click on users:

Warning: call_user_func_array() [function.call-user-func-array]: First argument is expected to be a valid callback, ‘MP_User::manage_list_columns’ was given in /home3/ilivesal/public_html/wp-includes/plugin.php on line 166

Fatal error: Call to undefined method MP_User::count() in /home3/ilivesal/public_html/wp-content/plugins/mailpress/mp-admin/includes/uzers.php on line 71

Currently I am testing the functionality of wordpress and have no users. Therefore i added myself but i received and error when trying to validate my email address seen below:

Fatal error: Call to undefined method MP_User::get_id() in /home3/ilivesal/public_html/wp-content/plugins/mailpress/mp-includes/mp-mail-links.php on line 128

Any help would be greatly appreciated. Thanks.

ian