If my key fob doesn't work...
 

Was in need of shifting the car to let a van out yesterday so i jumped in, turned the ignition, pressed the radio button on the key fob, but absolutely nothing. The immobiliser wouldn't deactivate. I tried it a couple of times but still nothing, then one more attempt and it worked and the car started. Fortunately it turned out that the battery casing on the back of the fob had become loose whilst the keys were in my pocket and so the battery wasn't seated correctly. Once the casing was tightened the fob was back to normal. Is the key fob the only method of getting the immobiliser to deactivate and start the engine? :wonder:

If she's a v7 or later UK car they often have a coded keypad in one of your storage areas. If it's an aftermarket unit you should have a touch key as well as a remote, if the touch key is missing it's always worth getting a replacement just in case :)

My bugeye has a 4 digit code which activates/de-activates the alarm (proved this), but I cannot get it to unarm the immobiliser - is there a special sequence?

Thers
 

No special sequence as such to deactivate the alarm if you know the code. If you haven't changed it yet then you could try 1234 it worked with mine and the dealer had actually written the 'supposed' code on the card they gave me when I took the car off them.
There is however a special course of action to change the code and if you need more info on this the pm me. I got a booklet about the cat one alarm and I have a 04 WRX