Every so often, a certain lock wouldn't work (lock/unlock) with the remote fob, but it would always work manually. This would come and go. Now the front driver side door has stopped responding to the remote all together. As of a week ago the front passenger side door stopped responding to the remote as well. They both work manually, but neither respond to the remote or the unlock/lock button inside the car. What's going on? Is it an actuator problem?