power locks acting up

I recently bought a '96 sentra GXE, and the problem that i'm having is with the power locks. they seem to do whatever they want, whenever they want. meaning they will pop open spontaneously, to the point that i lock my car when i park it, and return to find it open - nearly every time. i took it in to the dealer a few weeks ago, and they said they couldn't see anything obviously wrong inside, but the frequency of these episodes has increased since then. i've heard something about it could be the wire bundle in the driver's door. any other thoughts, besides cutting the power locks altogether??