Okay, I had absolutely believed that I had tried making the call to my savePos() function to try to diagnose whether the signal had something to do with it, yet when I disable the connect()ion altogether and call it explicitly, now these APIs want to behave like good little children and do what they're supposed to.

So, essentially I shot myself in the foot by handling this with modelAboutToBeReset(), which implicitly trashes the internal cache of visible indexes.

D'oh! Argh, etc.

Thanks for the help, folks.