I have just attached my new monitor in DVI-0, while my old monitor is on DVI-1. I have configured my new montor to be the default one and it works most of the times.

Something when I start a new application it starts in my old/secondary monitor. How can I make sure that all new applications are started in the main monitor?

Clicking on Kmix in the system tray opens kmix audio setting not in the monitor that has the system tray, but the secondary one. This is a bit strange. Same goes for my KDE Display Configuration lying in the system tray.

Somehow it seems setting a screen as default only has effect on where the panels are placed.