Immobiliser interference

Firstly, apologies to those that think I can't be bothered to check out the threads on this topic but I have done and just want some good advice as to how to negate this particular problem.

Went to my local shop the other evening and didn't even bother locking the car as I had three dogs in the back and was only getting a bag of peas!

Came out, put key in ignition and nothing happened. I have changed the lock barrel a couple of months ago but swapped over the coil and it has been fine up until now.

Disconnected battery - re-connected - swore - walked home and phoned AA to come and get me.

I had a feeling it could be radio interference but how to tell unless the car is moved out of the area.

AA man rolled up some time later - did all checks - I mentioned RF interference and asked if he could tow me home - only a about a mile!

Strangely - AA man got a bit ****ed off as his alternator failed just when we connected the tow.

Got home - unhitched - AA man said alternator on his van was now working and ....... my car started unlocked did everything it should do.

What I would like to know is....apart from which tosser is causing me grief, can anything be done to change the immobilser frequency so that it will be clear of all the crap RF which seems to be about.

Failing that, if you use the EKA code to get in does this automatically mean the engine is "live" and not still immobilised?

Sorry to go on but thought as much info now may help any replies - thanks.

if yu had read the threads, then yo will know of the various solutions, such as which lead to disconnect, or which part number to replace your BECM with.

Thanks for your help.

Reading the threads it seems in my case the immobiliser can be re-programmed so no need to replace any BECM? Is this the case?
If so, does this have to be done by a dealer or can it be done by someone with a Nanocom?

Thanks.