Mecanum drive cartesian problems

[broswen]

We are trying to use the mecanum drive cartesian method provided by wpilib. We are having a problem with the axis in the controllers not working properly.
We are using an xbox controller with 2 joysticks instead of a flight stick with a rotational axis. We are using the x and y axis on the left stick for the x and y variables called in the method and the x axis on the right stick for the rotation.

What is supposed to happen:
The left stick controls forward/backward and strafe left/right.
The right stick controls rotation.

The problem:
For example, when I push forward on the left stick the robot turns, and when I push left on the right stick it strafes.
When i push the left stick left/right the robot spins wheels but its not the right direction and doesnt move.

Has anyone successfully used the wpilib mecanum drive methods, and could you give us some tips?

We do not have a gyroscope set up currently and that variable is set as 0. Would that affect anything?