[frostygt]

ok so what was replaced last time? the whole transmission or just something like a soliniod pack?

and the other thing is, with these transmissions being computer controled you need to have it scanned to see if there are any trouble codes in the transmission control module... not all trans codes will turn the engine light on.
also if the tech knows what he is doing he can look at the sensor info to see if there is a problem there. sensors being off will cause drivability problems but not always set a fault.

so long and short of it all your going to have to take the car in to either a good dealer or good transmission shop simple because with automatic transmissions there are to many fault posibilites to diagnois over the internet.