Hi.I have a little problem with the VRDeviceOrientationArcRotateCamera and GUI.  
	Here is the situation: http://www.babylonjs-playground.com/#X1WNDK#3. Please click the check button to change camera. Now comes the problems  
	1. Gui seems to respond only on left camera, and I don't know why, but here seems to be the checkbox button.  
	Please let me know why this is happening. Thank you.