When I start the installer from a terminal using java -jar ..., or by double-clicking the installer jar in Finder, the installer windows always opens in the middle of the screen and suddenly moves to the bottom left corner.

The same happens with the Beta1 installer. My OS installation is only 1 week old, so I don't think I have some strange settings from the past.

See the screencast here: http://screencast.com/t/7ctaymGmvx