Problems Starting 2001 V40

My 2001 V40 has intermittent problems starting. Sometimes it would start immediately, sometimes it would take 3~5 tries before it would start. A few times it won't start altogether. I changed the battery, and the problem still persists. I later noticed that its the immobilizer that was failing which is a theft deterrent system that prevents the car from starting if it thinks it's being stolen.
Apparently, faulty immobilizers are a common problem in S40/V40s. You can also tell on the dashboard where in the lower right-hand corner, there is flashing car icon with an "X" over it. This icon means the Immobilizer has been activated and hence the car won't start. In the Volvo-forum website, someone suggested locking and unlocking the doors five times with the remote, which sends a reset signal to the immobilizer. I tried this several times myself, and it seems to cure the problem each time. I suggest you also check out the S40 forum, as there is a thread on this issue as well.