Nope, you are using it correctly. The __db.* files being gone is correct. Looks like you're pretty much SOL. I'd be fairly certain the SuSE Linux BDB doesn't have all the required patches, either. I would seriously advise building your own BDB and OpenLDAP release on that server.
SOL is new one me, I'm guess it's not good.
Remember that my original query is that clients seem to be accessing bits of the database that slapcat can't see - I just checked that ldapsearch can see those entries (though I can't see the shadowPassword field - looking into how to do that). But slapcat doesn't list them, and that's weird, no?