I've never had any problems with mine, none of the high winds shenanigans or anything like that, then yesterday the alarm went off while it was parked in a bad area. Sprinted out (in the distance from the front door to the gate i had built up a crazy rage, that's not like me, guess i'm sensitive about my car!) only to find there's noone around and the car's fine. So i reset the alarm (and my temper).

5 mins later, same again. Checked all windows, doors, bonnet, boot, all fine. Driving home we noticed a fly in the car. Opened the window to get rid of it and it's not misbehaved since.

Are they really supposed to be that sensitive?

I had same issue (except that I didn't really sprint out ) last week. Obviously alarm is sensitive enough to detect fly in car. I had fly or two in car last time, and alarm went on few times. After I got rid of that fly, there was no problems anymore, so based on this, I would say it's sensitive like this.