Turnigy Plush 18amp version

I recently bought two Turnigy Plush 18a escs to replace some that I burned out on my tricopter. I put them on and noticed that they were smaller than the other one. The new ones were version 4.3, while the old one was version 3.1. I turned it on and the 3.1 started smoking and melted half the casing. Now I need a new esc, but no website I can find specifies the version, although the picture always shows the 3.1. Did the differing versions bust my esc? I haven't gotten this thing to fly yet, and have been through 4 escs, a motor, and a servo. I would really like something to go as planned.
Thanks-
MotorMann

-I've already posted this on three other forums and haven't gotten a response yet for months.