@Bernhard: try going to System → Preferences → Appearance → Visual Effects → None; the Appearance Preferences dialog’s title bar buttons change to a single round close button. Then press Alt+F2, and you’ll see the Run Application dialog’s title bar only has a single round close button, too.
Now enable visual effects again and check the title bar buttons.
@Bernhard: try going to System → Preferences → Appearance → Visual Effects → None; the Appearance Preferences dialog’s title bar buttons change to a single round close button. Then press Alt+F2, and you’ll see the Run Application dialog’s title bar only has a single round close button, too.
Now enable visual effects again and check the title bar buttons.