While in the hybrid's Eco mode and slowly accelerating from a stop, the engine overrevs because the automatic 6 speed transmission hasn't shifted from 2nd gear to 3rd gear and the engine is revving too high. I hit the paddle shifter to actuate an upshift and the transmission shifts into 3rd gear. I'm pretty sure the vehicle has operated this way a couple other times in the last few months. This particular time I was very cognizant and noticed which gears the transmission was operating. With a little over 9,000 miles on the vehicle, the local Kia Service Manager will have the issue investigated during the 10,000 mile servicing.