Sounds like everyone in this area of photography has been spooked at one time or another.
Last time I was down Wilson's prom way I'd done some google scouting like I do on most trips, there was one property I was keen on getting access to, the land also happened to be near a building (turned out to be farm house) so when I went past during the day I decided to stop in, explain what I do and asked if I could go on his land (I was also worried about potential for a bull being in the paddock) he was fine with it, I offered to email him some pics and when I got home I did (I never got a reply).
From that experience I will try and ask for permission in future apart from looking at you a bit funny most people won't mind and anyone that would mind I don't think I'd like to be found on their land late at night uninvited
