[Alan Anderson]

If turning left and right works properly but front and back are reversed, I would guess that you have your PWM connections swapped. The basic 2012 robot project wants PWM1 to go to the Jaguar controlling the left motor, and PWM2 to go to the Jaguar controlling the right motor. That's the first thing you need to check, before you worry about which direction the motors are running.

Or you could just decide to call the other end of the robot "front" and be done with it.