Problems with my automatic 95 N/T Please Help!

[Lou95RS]

I bought a 95 eclipse RS about 1 year and a half ago, and like 7 months after it began stalling sometimes when i would stop at lights, until one day it simply didnt start. The mechanic said it was the engine computer so he changed it and since that day, the car has been having a few problems it didnt have before, and i just wanted to know if some of you could give me any ideas of what could be the source of the problems.
The thing is, now when i turn on the A/C revolutions go down a lot, and when i turn it off, revolutions go up a lot. i put in a new ISC but that isnt it, and also like when i am going up a hill if i let my foot off the accel pedal, the transmission begins to shift and if i step on the gas rpm go up but car doent move like if it were in neutral(just for a second), and then car shakes and starts to move. When i come to a stop in a light when i am like down to maybe 10 or 5mph transmission begins to shift and it feels as if the car were being pulled by the back, and its a pain in the ass cause i cant decelerate to 0mph smoothly.

The thing is that i was checking the numbers on my old bad computer and the new one and the big last 3 numbers are different, the rest of them are the same. Is this supposed to be like this?? or do all the numbers have to be the same.
Or maybe my tranny computer is bad, or what else could it be?? Why doesnt my ISC do what its supposed to do??
Please help!!

[LaFemmeDSM]

As far as the tranny always check the fluid first, it should be at the correct level and clear red if not, just changing it could clear up that problem.
First things first, are you getting a check engine light?
When you turn on the air the RPM's are supposed to go down a little then the computer is supposed to compensate. It could be the replacement computer, 2 ways you can find out. 95's are supposed to be OBD-I and 96+ are OBD-II (the computer should say it on it somewhere)it is possible they got it wrong but i'm not sure if an OBD-I car would run with an OBD-II computer. I doubt there is anything wrong with the ISC if you replaced it and it didn't help, the ISC is controlled by the computer.
Try taking off the battery cable for 15 min. then go driving for a bit and see if that helps, it could just need to be reset. (becareful if you have the Infinity stereo system, get the code for it before taking off the battery cable.)