Tranny problems!

I have a 91 accliam v6 and when I frist start it its fine but when it gets up to running temp and i get to where im going and shut it off and do what im there to do and start it up and put it in gear it bangs into gear hard and its stuck in first. But if I shut it off and then start it agian its fine or I have to do this 2 to 3 times to get it to work right. I also can be going down the road and it goes into nuteral and when I get it to a slow enough speed it will drop into first agian and I have to stop and shut it off and restart it to get it out? Please help!!!!!

oh yeah its automatic with overdrive

It sounds like a programming problem you are having; go to a local Chrysler dealer and have them take a look at that