Solaris - DMI error

We kept getting the following error on a number of servers (all running Solaris 10 update 10):

snmpXdmid: Registration with DMI failed. err = 831

After hunting around I found that the error is related to one of two issues:
1. Missing patch (138361-02 or later), or
2. Database files need clearing out

Having checked that the patch was there:
# patchadd -p | grep 138361-02
Response:
Patch: 138361-02 Obsoletes: 128415-01 137019-02 Requires: Incompatibles: Packages: SUNWsacom SUNWsadmi

(Checked MOS to see if this was the latest patch, which it was).

Which left clearing down the snmpXdmid database:
# svcadm disable dmi
# rm /var/dmi/db/*
# svcadm enable dmi

Once cleared down the error disappeared......

References:
http://docs.oracle.com/cd/E19082-01/819-2379/swmgrpatchconcepts-30/index.html
https://forums.oracle.com/thread/2242176