Transmission?

Ok, so my problem is everytime i start my car, put it in reverse to get out of the driveway, then when i go from
reverse to drive, my car does this jumping thing, ill press on the gas, and it wont go, then a couple seconds later,
it will jerk pretty dang hard and go... it did it a couple of times in the summer, then stopped, but this winter it has
been doing it constantly, everytime i come to a complete stop, then go, it does it... The other day i drove it to
Topeka, and it completely died on me at a stop light, i had to start my car again, and it jerked and went... Its
annoying as hell, does anyone have any ideas? Ive put Lucas Transmission Fix in it, it seemed to help a little, but
the next day it started in again... winter of 07' i put a new battery in it, then found out it was actually the
alternator that was having problems, so in summer of 08' put an alternator in it.. did fine after that but thats when
i started having the "jerk an go" problems.... What do you guys think???