Yes, Phil, I get much the same thing. That's why I live by the motto:
"'Tis better to ask for forgiveness than permission."
;)
I also carry my palm pilot around with some of my best photos on there, to show people I am MORE than a GWC (guy with camera: a disparaging comment models use toward wannabe or especially creepy photogs). After showing people some of my photos, they sometimes excited enough to show me things I might have missed without their help!
But yeah, when security gets involved, I put the camera down and just say "oh, ok. Now that I know your policies, it's not a problem" And 70 percent of the time I've already gotten the shot I wanted in the first place. ;)
A striking image, Paul! Wonderful colours and comp!
I don't know about America, but, these days, in Australia, I hesitate taking a lot of photos in buildings etc.
Recently, I was taking some photos of the outside of a new shopping centre, when, from nowhere, a burly security guard appeared and asked me to stop taking photos. I explained that I was a photographer simply taking some photos of the design features of the building. He told me that if I did not leave he would call the police! What a world we now live in!
I think this image could benefit from a well plotted crop/rotation. There is something good you've captured here; I'm less certain about its current presentation. I hope this is useful.