Burnin are you having this kick problem using the 2Box on its own or only with using it for Rock Band? Just want to make sure your problem is with the trigger/head and not because you're trying to play a computer game with it.
We need to make sure you understand how those settings affect the operation and you're not just trying to copy other settings. Here's my understanding of of how the settings actually apply to the operation of the module, hope it helps you figure it out:
Curve: Leave the curve setting at normal before changing other settings - this setting should be altered only once you are happy with gain and threshold.
Gain: Should be set so that your hardest strike of the drum only just lights up the top level under the unit/trigger page. Remember, try to keep the gain at 0 at first and make small adjustments as you go.
Threshold: Should be set high enough so that no double triggering occurs, but low enough to register your softest strike. A value of 36 roughly is a good place to start.
Trigger Type: Should be set to Kick 1 or Kick 2. Kick 1 has a faster response, kick 2 slightly delayed according to the 2Box manual. I use Kick1.
Curve: Once you are happy with the triggering, adjust the curve to fine tune.
Cabling: Make sure the stereo jack has its plastic washer tightened at the input port, and check the stereo cable works on another device.
Rack/Bass drum connection: Make sure the bass drum is firmly secured to the rack - there should be minimal movement when striking the pad.
Head Tension: Ideally it should be at least medium tightness, I have mine tuned up medium/tight and the response is great, the slacker the head the less responsive it will become, although it will still trigger of course.
If you still can't get it triggering properly, the sensor or cabling must be faulty. - I say that only because I have had both the MKI with foam and MKII without foam and both triggered perfectly with different settings, so more than likely, for you its a sensor problem/sensor postioning problem, or a module settings issue.