I am setting up my new SkySafari 6, and I am very satisfied, but I have found a small bug: the subsettings under 'Show Horizon and Sky' include 'Show Daylight', but the daylight is shown even when 'Show Horizon and Sky' is off and 'Show Daylight' is greyed out. In order to remove the daylight, it is necessary to switch the main setting on, set 'Show Daylight' off and then switch the main setting off again.
I think this is a general problem because I believe I have seen similar behaviour with another main setting where the subsetting is not switched off together with the main setting, but now that I look for it, I cannot find it again!