2005 Toyota Corolla Rough idle when braking

Whenever I come to a stop in my car, my engine idles rough for a couple seconds then idles normally. It happens almost everytime I stop. But it only idles rough at the end of the stop for a couple seconds. I took it to the dealer and they said everything checked out fine. It is bothering me so much, though. Somebody said it sounded like a faulty solenoid. Do you know what could be causing this problem? It is driving me crazy!