S40 V40: Car won't start (immobiliser)

[V40 Owner]

Argh!

Only got the car a few days ago, and now it won't start. Immobiliser light flashing...

Of course, part of this may be my own fault. Yesterday, and today, I was seeing how far away the fob will open the car and then all this happens. I read in the helpful owners manual:

Do not try to operate the doors from too great a distance or you may trigger the immobiliser

Among further weirdnesses, I noticed the other day that the rear fog lights don't work. I got a Haynes manual with the car (Is this a good or a bad sign?!) and looked it up ... Fuse 4 in the bulkhead - horn, alarm, rear fogs. Funnily, the horn doesn't seem to work either. Perhaps the fuse has blown or the previous owner disconnected it. Haven't dared look yet unless I unearth a whole series more of problems ...

So. It looks like I have a car that MAY have an alarm problem, and the immobiliser seems to have tripped. How do I reset the immobiliser?

Some reading around here and there suggested going through the lock/unlock cycle five times with the remote should reset it. No joy there. How exactly are you supposed to do it? I mean, people say 'lock/unlock' which implies one must first unlock the car; so is there anything special I should do in that respect? i.e. should I unlock it with the key or the fob? Should I relock it with the key first? I dunno ...

Other posts on here suggest that faulty bonnet switches and/or faulty wiring under the radiator can cause the immobiliser/alarm to trigger; same story for boot. At the moment I haven't had a look at any of that as it was suggested elsewhere that if left for five hours the immobiliser would reset, so I am trying that just now ... unless anyone has any better ideas?

Hope someone can provide some helpful suggestions, thanks ...

e2a: Forgot to clarify - the car is an S-reg (1998) 2.0 V40 ... anything more exact than that, then I'd have to go downstairs and look at it ...