Traveler creates a device profle document in each user's mail database to keep them across devices getting cleaned up/reaped/removed. As they all have the same "user", you can expect one per device in this database. Being in that database is the "user" part.
HA or not won't matter.
You should be running "tell traveler user <username>" and make sure it is access to everything. You can also use tell traveler dump for the user to see what Traveler shows in there. Most errors for access type things will be shown in that output. User (alias of show) will be in the user dump too.
Feedback response number RSSN98CQEU created by Robert S Sielken on 06/04/2013