Hi Mike
Basically jOpenSim is using almost the same database table structure like the built in profile v2 from OpenSim.
The difference is, that the tables reside in the Joomla database and not in the OpenSim (robust) database.
Unfortunately I dont have any database running anymore with these tables to be able to complare completely.
If you could make some backup of your OpenSim profile database tables (I think they are usually named os_profile_*) and send it to me (foto50 at jopensim.com) I can create a nice migration query for you if you want
Greetz
FoTo50