Keyless Entry Randomly Activates

I need your help. I'm about ready to tear my hair out. I installed a keyless entry system on my 1996 Toyota Previa DL S/C. Everything works like it should (simple lock/unlock with parking light flash), except for one irritating thing... It locks/unlocks itself at random times, no matter what the Bean is doing. Sitting, driving, parked, whatever. As I'm driving down the street, sometimes it will get on a roll and lock/unlock itself 4-5 times in a row. Then, it won't do it again until I push the button on the remote. Or, like tonight, I was working on seeing if I had a short somewhere, and it was locking/unlocking itself randomly.

Someone just suggested that perhaps the unit's antenna might be over-sensitive and picking up signals from the remote (which is usually hanging from the keychain in the ignition). Should I cut the antenna off the unit?

I'm open to all suggestions and ideas!

Are there any wires still installed from the old alarm? If so something could be activating the door locks, or getting a voltage spike from your new alarm.

Chris,

I've cut out the old wiring harness. What kind of wires would produce a voltage spike? I mean, what kind of old connections would I look for? I can't say that I disconnected all the old connections because I'm not sure that I did. All I know is that I've pulled out the old harness. Do I need to tape all the wire ends even though they're cut?

Kathleen