Volvo Repair: When engine is turned on, it rotates but dies out before running properly, volvo v70, going in the right direction

Question
We have a Volvo V70 2.4 SE from year 2000 that has run 80,000 miles. It originates from St. Louis, USA, but moved with us to Denmark in 2004. The problem that we have with the car happens periodically (6 out of 10 times) and is experienced as follows: when turning the car key in the ignition, the engine rotates, but it dies out before running properly. After having had the car keys and software in this connection changed, the problem was gone for a week. Now it is back again. The lock has not been changed. Only the keys. The repair shop is frustrated because they claim that it is problematic to deal with an American Volvo in Denmark, but they think that it has to do with the communication between the key and the ignition/engine, but apparantly they do not know how to fix the problem. Can you help? Thanks a lot for your time.  

Answer
Your best bet is to replace the immoblizer module.  It is what communicates with the transponder in the keys.  You may also want to replace the antenna ring around the ignition lock.  That is what picks up the transponder signals.  Those are the only other components in that system, and since replacing the keys helped before that would more than likely be your problem.  It still could be somewhere else but if they think its an immobilizer issue (with the keys) than maybe this can get them going in the right direction.  Good Luck.

James