Why is my 2004 Rav 4 Hesitating on accell from stop?

I have had my Rav new since 04. It has been a great little SUV, sure footed in the snow. I live in NY near Buffalo. Any way the car began to hesitate a couple months ago. I had hoped it was gas issue but I guess not. I took to West Herr in Hamburgh NY. They drove it and ran diagnostics and told me nothing is wrong. They recommended an air filter and trans fluid flush. Okay it's due 25,000 miles. I pay 200 bucks and the car is still hesitating. Needless to say I have lost my faith in West Herr Toyota. Is any one knowledgeable on this problem? I know there are many others experiencing this problem. Has some one found a cure. Any help is appreciated.

I bought a 2006 Rav4 in April, and it has been hesitating off and on. I was finally due for an oil change so I brought it into the dealer today. It told them it hesitates at low speeds - leaving a stop sign up to about 30 MPH. They had the car in the shop for the whole day and it came back as OK- Normal. Its very frustrating because it didn't hesitate when they drove it (of course!). I told them to keep it and try again on Monday. I really hope they can figure out what's wrong. They said its a computer chip that will "learn" my driving patterns and it should go away in time. I had a Honda for 10 years and it always drove very smooth. I am definately not happy with this.