White Window behind Standalone Build

I just made an OS X Intel Standalone Build and noticed that there’s a white window behind the game window - What’s up with that?

And if I switch to a different scene and then back to the first scene (the one that sets the screen resolution) the game pops up in a new window and I now have 2 empty white window behind it…

Anyone else ever ran into that?

Screen.SetResolution(320, 480, false); seems to be what’s causing this.
Setting the resolution in Edit > Project Settings > Player and disabling the Default is Fullscreen check yields the desired result though (thanks to ToreTank!)

PS: I’ve reported a bug on the SetResolution issue (313518)