I have a 2007 Sienna CE and I really like the car

.....except.....
I have a problem with a creaking noise coming from my sliding doors (near the latch, I think). This noise is almost constant...any little bump, braking accelerating, turning a corner causes it.
I have had it into the dealer twice...once in July and again today. The noise was gone when my wife picked it up this afternoon, but the noise was back this evening. Dealer has been lubricating the door seals, but I think they are only treating the symptom...
Anyone else have this problem?