Vibration

Hey Bob and Ken.I have an 04 honda accord ex, 4 cyl with 40,000 miles that's been acting up. On cold starts it idles pretty much ok, maybe sounds a little different, not sure, but when put in gear it really vibrates the sterring wheel and gas pedal. When driving the vibration seems to go away untill I stop at a stop sign or a red light, then it vibrates again. After driving a few miles and the engine warms up the vibration goes away, it can be felt slightly but not as bad while driving but not at all when stopped. I would compare the vibration to holding an electric hair clippers. So anyways, it vibrates on cold starts but only when in gear, the engine warms up and it all but goes away! A honda repair shop checked the motor mounts, and also said they put on an idle smoothing kit. Never heard of such a thing. But it didn't help, can you guys help me? Thanks, and hope you're having a good day! P.S. No engine light.