What determines sorting in QFileDialog, and how to alter it?

QFileDialog lists files in an odd order. We wonder what determines the default sorting. Attached image: how the heck is this sorted? Fine for Martians, but we Earthlings want to see files sorted by filename, and by default when the dialog appears, without the user having to click anything first.

We may want to define our own comparison methods at some point. Is that possible? If not, at least what kind of hooks into sorting or file attributes comparison can we get our hands on?

http://www.aoc.nrao.edu/~dwilson/temp/goofysort3.png