DotMailer Extension Conflict
DotMailer - Truly Integrated Email Marketing 1.4.0
Resolved; with an update of MageRewards to latest version
When a customer is captured the synch allocates a .dotMailer ID and then saves the customer record. This causes the MageRewards sign-up rule to trigger, even though the customer is not new.
Update MageRewards to latest version 126.96.36.199