I fixed my problem with the immobiliser/alarm (see "306 alarm/immobiliser probs?")
I think I also know why the battery went flat in the first place, thus causing the alarm and immobiliser to kick in once battery was charged/jump started.
There is something dodgy with the electrics, and it is intermittent, but if I have the car parked, and no key in the ignition at all, sometimes, I can turn the car heating fans on, and the rear window screen heater, and these usually only work when the key is in and turned round two clicks.
The problem of the rear heater being able to be turned on and off, even with no keys in the ignition seems to have disappeared but the fan related problem still remains, albeit intermittently.
I have made sure that when I lock my car at night that all the lights, and there switches are off, inc reading light. the radio is off, as is the heater fans and rear windscreen heater.
I also got the battery changed this morning as when the guy came to jump start me I asked him to look at the battery and he said it looked like it was running on only 2 cells, so after he had gone I went to an independent motor place and got it changed.
Even with all the electrics off yesterday, the battery still lost enough power somehow for it to need jump starting this morning. I am not sure if this is down to leakage somewhere, or a bad battery.
I will see if the car is ok tomorrow morning.
Any ideas on why I can have the heater fans on even though the car is "completely off"?? Sometimes I can hear a buzz/crackle sound coming from behind the dash when the car is "completely off" too, but no relay clicking on/off. It is strange, as all these problems developed overnight on Thursday just gone (5th feb).
Sorry for the long post, any ideas?
Karl