Single-table inheritance

Has there been a change in the way AAF handles single-table inheritance?
Using trunk, Model.find_with_ferret does not (for me, at any rate)
return any instances of ModelSubclass, while
ModelSubclass.find_with_ferret works as expected.

I also see that find_with_ferret no longer takes a :models argument, so
I can’t manually force AAF to look across multiple classes. Is there a
new way of declaring either inheritance or multi-class searching?