Hi, I had this problem back in 2008... Car sat at the dealership, unable to be fixed for almost 4 months!!!! They changed every imaginable part including the the computer to no avail... Eventually, 4 months later and a half striped down Crossfire they located the cause. It turned out to be a short in the door switch!!! The drivers side door switch (the one that turns off the interior light when the door is closed) was shorting out and triggering the alarm. It would even do it while I was driving the car. Anyway, I hope my misfortune helps you find the root of your problem. If it's not the door switch, look at any other switch that is linked to the alarm system.

Best,
Dave