Patrick,

I see the problem...I'm always storing the absolute value of the RotationAngle when this property gets set.  Thus, if you had previously set the value to -30, it would have store the value 30 in the RotationAngle's private 'angle' member.  Then, when you set the RotationAngle property to 30, you can see that nothing will get set, since it thinks the last value (angle) is 30.  Thus, when you invoke Rotate(), it uses the last value stored, and it keeps using that.  Thus, when you set a slightly different angular value, then Rotate() works as desired.  Dohh!!  I'll get this fixed asap. :)

      get { return angle; }

      set

            if (angle != value)

                  int fractionalRotation = 0;

                  double angularDistancePercentage = 0;

                  angle = Math.Abs(value);

                  if (angle == 0)

                        return;

                  // Figure out how far in ticks the motors need to turn...

                  // Number of complete rotations:

                  int fullRotations = (int)angle / 360;

                  // Fractional Rotation left over:

                  if ((angle%360) != 0)

                        fractionalRotation = (int)(360 / (angle - (fullRotations * 360)));

                  // Fractional Distance:

                  if (fractionalRotation > 0)

                  // Final Distance:

                  double finalDistance = (trackCircumference * fullRotations) + angularDistancePercentage;

                  // Determine how many ticks it'll take to go the specified distance:

                  double revolutions = finalDistance / wheelCircumference;

                  distanceTicks = (int)(revolutions * ticksPerRevolution);

                  // Set the distance (in ticks) for each motor to travel...

                  if (value > 0)

                        // Right Turn Clyde!

                        motor1Distance = distanceTicks; // Left Motor

                        motor2Distance = -distanceTicks; // Right Motor

                  else

                        // Left Turn Clyde!

                        motor1Distance = -distanceTicks; // Left Motor

                        motor2Distance = distanceTicks; // Right Motor