I've seen, or heard about, this on a couple of different models. The issue is the autoboot environment variable is being set to false in the factory. The way to check is to go to the LOADER prompt and type: printenv
Look for the autoboot variable. If it is set to 'false' then type: setenv autoboot true. You need to do this to both nodes in an HA pair.
The explanation I was given is if the factory thinks the system will be running Cluster-Mode then they turn autoboot off. Haven't been able to confirm this, but changing the variable does resolve the issue.