Automatic Transmission problems of the 2009 Kia Motor Optima

When driving car is ok, but when you slow down to around 20 mph the car jerks , but after car I driven for around 10-15 miles it doesn't do it.

2009 kia Optima lx/ex sedan 4 door transmission 15,000 miles extreme hard down shift when slowing to a stop from second to first. , almost like it throws the car into park, enough that it could throw you into windshield if not wearing a seatbelt. The dealer can not find the problem, it only happens 20% of the time on ice and slick roads it can cause you to lose control of the vehicle. This has happened to me several times.

Bought a kia Optima a few months ago and recently it has developed a dangerous shifting pattern when down shifting from 2nd to 1st about 20mph it jerks the !@#$%¿. Out of you and if you happen to be braking at the time you meet a snap from seat belt as you fly towards windshield causing sever neck and back pain this is getting worse , dealer willing to fix but kia is ignoring the issue as I have heard of others having same problem , I have been told by dealer its probably just computer oriented but kia has to authorize the repair , contacted kia and as expected there computer was down and they could not help me!.

I have a 2009 kia Optima lx when I go to brake around 20 mph it feels like the car is downshifting hard causing me to jerk in the seat. It does this all the time I do feel this is the transmission and I am taking it to the dealer to be serviced.