Central locking keeps draining my battery

went to use my 4.6 1996 RR only to find the batery flat - put it on charge yesterday, all going well, battery charger working ok, took it off charge and the car started up all ok.
Locked the car went to it this morning and guess what - dead battery.
The battery is only a couple of months old and according to the charger is charging all ok. I noticed when walking away from the car the rear door locks on both rear doors but not the boot are pulsing every 5 seconds or so.
l guess this has been happening whist l have been away from the car and so has drained the battery.
Any ideas - very strange that both rear doors are doing this, not the boot or front doors.
nothing has been touched electrical wise so not sure which direction to go apart from looking at the obvious such as relays etc!

have taken out fuse 20 fronm the drivers seat fuse box, this has stopped the rear door locks pulsing. Car now telling me 35mph max and the air suspension seems to be non responsive!

do l need a re0set on a diagnostic machine or are there any fixes?

Dam thing

Mine occasionally throws a fit and locks the doors every few seconds. Whether by luck or what I don't know but the temporary fix for me is to put the key into the ignition, start the engine and unlock the doors with the fob. Locking and unlocking a couple of times usually clears it. I have noticed that it seems to do it if one of the doors is not shut properly or if one of the external door handles is not fully pushed in (if you get my meaning).

Are you definitely absolutely sure it's your door locking causing the flat battery and not the dreaded RF receiver? Mine sucked a brand new battery flat in a little over a week. Was a doddle to change even for me.