Car Alarm goes off at one location - post 9/11 question

Just today my car alarm has started to go off at a self storage center
I use. I've been there everyday the past week and just today anytime I
drive in to the complex and get mid way through the alarm starts going
off. If I turn off the car the doors keep locking and unlocking and the
alarm will go off after a minute or so. This continues until I drive
out if the complex. It does not do it anywhere else and does not
prevent me from starting the car while the alarm is going off, the
alarm goess of in valet mode where it never has before.

I've had the car for three years and the alarm was installed by the
dealer. Card is a 2001 Ford Focus and the Alarm is an Audiovox (not
great I know).

Being what the world is post 9/11 I'm wondering if something bad in one
of the storage centers could be causing this. I talked to the mangement
and they stated nobody else has reported any issues with car alarms as
of yet (its a slow place).

Before I make a phone call to a government agency to see if they think
this is something they might want to look in to I thought I'd check to
see if anyone out there has any ideas what may be causing this or if
something like radiation could cause this. Being it is a storage center
with at least a thousand units, the mangement stated they have no idea
what could be in any given unit that could cause this.