Land Rover Repair: Reseting alarm for 00 Disc II, factory radios, www pac

Question
Help! I have a 00 Disc II and some how I keep tripping the anti-theft causing the vehicle to not start. The first time this happened I towed it to our local mechanic because I had no idea what was wrong. It turns out it was the anti-theft. He reset it using his computer and it started just fine. I've had it back 2 weeks and looks like I have tripped it again. I guess I have 2 questions: 1) Is there anyway for me to reset the alarm myself so I don't have to tow it and 2) What could I possibly be doing to cause this??? The only thing I have done in the last 6 months is install an XM radio @Best Buy. Other than normal stuff .... That's it! Thanks for any help you can give me!?!?!?!  

Answer
Hi Coda Bruce,

I can't answer the first question:  how to reset the alarm once its triggered other than by using your key in the drivers door.

I believe you have answered the 2nd question yourself.  By installing a 3rd party radio, you may have opened yourself to a security breach.  It could be that the security ECU is looking for the radio security code and getting no response.  Here is a company that may be of service:
http://www.logjamelectronics.com/

Also try PAC mobile, they have a pdf on replacing factory radios that might reveal your problem:
http://www.pac-audio.com

Best of luck,

JOhnMc