Cannot redeclare date_token_list()

Received the following error message when adding a state machine action to a rule.

Fatal error: Cannot redeclare date_token_list() (previously declared in /var/www/drupal/sites/all/modules/date/date/date.module:354) in /var/www/drupal/sites/all/modules/token/token_cck.inc on line 226

Not sure if this is a problem with workflow_ng, token or date?

Token version = 5.x.1.10
Date version = 5.x.2.x-dev