Camry 2007 - doors could not unlock

I have a 2007 Camry with the lock on the passenger doors and back doors stopped responding to the remote key UNLOCK and the driver side UNLOCK button. I have to manually unlock the driver door with the key after pressing unlock on the remote key, then get into the car to manually unlock all remaining three doors. However, the remote key LOCK and driver side LOCK button are working fine. I can also open the trunk with the remote key. The issue is only with the unlock. I had the same problem twice some 2 years back and it became alright after I visited Toyota service center. Now I am facing the problem again. Visited the same Toyota service center last week, they claim rare and have not seen this issue even though I could identify the serviceman attending to me previously. Service center requested that I make appointment to leave the car for them to check and stated it might takes long time to investigate. My appointment will be about 3 weeks from now. It is very inconvenience especially when I have my children with me. Anyone else has this problem?