Unity 3d 4.6b New GUI system doesn't take touch when already a touch event is occurring in 3d scene

I know this is beta version but..

I have a Canvas->Button which works fine when I tap it normally.

I have a joystick in my scene which is drawn by separate camera other than mainCamera.

now, while i am operating joystick without leaving it, if I tap on he Canvas->Button - it does not respond. When I lift finger from joystick and tap on it, it works fine. Same goes for another Canvas->Toggle control.

It has something to do with the layering or anything else...I'm not sure?