Screen freezes until pointer is moved. Help please.

I hope there is a setting I've overlooked, because I really like your app. My problem is this: after an undetermined period of idle time my screen stops updating. Once I move the pointer the screen refreshes and all is well again. This obviously seems to be some type of sleep feature. Is there a setting to change the time until it "sleeps the display?" If I change to a manual setup or VNC will this correct the problem. Any workarounds? Any help will be appreciated. Samsung Galaxy Note 3 Android 4.3, but I had the same problem with my Note 1, so I don't think it is device related.