I have this car since 2005. it is W211. I never had this problem before. I went to local shop and when i wanted to set the alarm - nothing happened. i tried few times. when i pressed 'open' button - it flashed once. however 'close' didnt work at all... once i came back home it worked as usual. can it be some strong radio signal interference around that particular place which was screwing the keyfob? (need to note that i even sat inside the car and tried to set the alarm from inside - hoping it will reduce interference somehow).