For the past 2 weeks i have been having problems locking an unlocking the doors of my car usind the remote control key. First was an infrequent problem but when it happends if I waited for about 10 seconds and try to lock the doors again it will work fine. Now is almost constant, and is rare the ocation when the remote control will work. I try new batteries on the remote and try the second key too with no luck. Any ideas?