CodeIgniter DataMapper ORM unable to instantiate model object
The database schema had been used prior to switching to CodeIgniter. The first table had a name conflict (it used "lang" for a field name). The second table had no conflicts, and was failing only because it was the next DataMapper subclass instantiation coming after the model object with the problem. My attention was on the table/model that was failing, when in reality it was the one that succeeded that had the problem.
The fix was to check ALL model objects for conflicts, not just the one that is failing.