When starting Ensemble briefly flashing window at 0,0 before centering it on screen.

It does not happen every time, but happens frequently enough to be annoying.

This could be Glass issue, but my initial guess is that either Quantum uses Glass wrongly, or the JavaFX library uses Quantum incorrectly.

Wherever the issue is, its moderate in seriousness as it presents un-polished look for JavaFX apps.