Yep, there is but it was installed recently (2-3 months ago) and I have the problem since I purchased the car - more than an year now so I don't think it is related. Also the alarm that was installed is controlled by the original car key and integrates with the NATS system so it is hooked up to the main bundle of cables going to the Smart Entrance Control Unit and did not require any modifications to any other parts of the car. What it does is when the car is locked it triggers the horn and has a shock sensor in case someone hits the car or breaks the glass.
I will try to rule it out when I'm doing the re-wiring this weekend, I'll disconnect it and test w/o it, but I'm sure it won't make a difference