[Chris_Ely]

The twitching is most likely that the Talons are not calibrated. Calibration basically tells the Talons what input values correspond to full forward, full reverse, and neutral.
To calibrate the Talons (from the Talon user manual):

1. Press and hold the button labeled “CAL” with a paper clip. The
LED should begin to blink red/green.
2. Continue to keep the button pressed while moving the joystick
full forward and full reverse. You may do this as many times as
you like.
3. Center the joystick and then release the CAL button.
4. If calibration was successful, the LED will blink green several
times. If the LED blinks red several times, the calibration was
not valid. If this happens, the Talon will use the last valid
calibration values.
All calibration values are retained after power cycle or reset.