Locks '93 LS

The locks on my LS re-lock everytime I accelerate the car. This just started last week (it has been very cold) and I never had any problems over the 5 years that I have owned the car. Well just with the stupid dealer. Any ideas what could be causing this issue?

Thanks in Advance
Steve

I have a '93 ES. The doors automatically lock over a set speed. If you unlock them after that they will relock everytime you accelerate. Seems to be working fine.