Using it quite extensively yesterday and noticed that the video 2 window flashes white quite frequently. Almost every time i click toggle rotation screen it will and it also does this while playing a song. (Really quite trippy)
It does not make a difference if it is on my external monitor or if i drag it back to the main screen.. It is only the video 2 window that does this... Video 1 window does not have any issues.
I have the newest and highest model of iMac without any video issues what so ever... I use kJams almost every day and have only noticed this upon upgrading to kJams 2