99 TJ shifting problem only in the cold???

I have had a 99 TJ for a few years now w/ a 4.0L Auto. It has about 75K on it now, and I have noticed that when it is really cold it shifts terrible and slips between gears for quite a while until it gets really warmed up. I am going to try to change the tranny fluid/filter, but I need some help if I should get the tranny looked at b4 my extended warranty runs out. Has anyone else had this problem, b/c the Jeep dealership said this is "normal". I really don't like it and if it is major I want the warranty to pay for the new tranny, not me. Email any help to [email protected]

Thanks

Automatic trasmission may react such way when they are on LOW level of transmission oil.
Check your oil
Have you replaced the transmission oil and filter? They should be due big time.

If everything is good, then there is a sensor that kicks in, just warm up the car before driving, or change that sensor.