thought i had an immobiliser problem myself just this evening so found this site to try and help me. turned out what i and a few others who where with me at the time thought was an immobiliser fault wasnt. first off i wasnt gettin a red light on the dash indicating the immobiliser was on. so phoned a mechanic and got some advise. he thought maybe the starter had packed in, but told me to check for loose connections. he explained the starter in the rover 200 (mines a 220d by the way) was above the gear box which is situated below the air filter( big black rectangular box with clips on it). the starter is a bit ocward to see but easy to feel around it. preper to get hands dirty and feel for cables. as i was feeling i found a small plug which made a clicking noise as i pushed it. tried turning the car over and it fired up 1st time, happy days. fingers crossed problem solved. oh and this didnt cost me anything bar an hour of my time lol.