There is quite a bit of code, as the subclass is for drag and drop. It would probably be easier to give a url to the project...

But, I found it was caused by the signal currentItemChanged(current, previous), or just the way I was using it. I only made reference to current, and a quick "if (current)" fixed the problem. But why would the current item be null in one sort order but not the other? Is this a Qt Bug?