crazy power door locks!

My uncle has a 2000-2001 plymouth neon. The power door locks are going crazy. whenever he drives the door locks keep locking like if someone was playing with the switch. I heard about dodge having this feature that when you go over 5mph the locks will automatically lock. I don't know if there could be a problem in this system or what. Anyone out there has had an experience with this problem? Any replies are appreciated!