Electronic lock problem
 

With my 2000 CRV with the electronic locks (using key can lock all locks), it is getting very erratic in working. Sometimes when I unlock the car, only the driver door unlocks other times all unlock. Using the lock button inside the car, it also may or may not lock. Sometimes (usually) I have to walk around the car individually locking all doors. Occasionally, the inside button to unlock will work but only if the door is closed. I suspicion there is a single controller. What do I check or change to fix this problem? I am quite sure that all the locking mechanisms in the individual doors are working well, but it seems to be a matter of a central controller. Ideas?