Unfortunately what you're experiencing is a known bug (#2290) where Propose spontaneously plan at registration: is not functioning. The best I can suggest is disable the plan from showing at registration at all with Allow registration: set to No. When logged in seams functional and only displayed with direct URL as per "Upgrade" configuration.
You're also running CB 1.3, which is out of date. Please upgrade to CB 1.4; this won't resolve your issue however, but will resolve other known bugs with CB it self.