Why won't the APC40 and Kore 2 controller coexist happily?

I 've been using Ableton Live with the AKAI APC40 controller on my Mac Book Pro for a couple of years now, and recently I bought Native Instruments' Kore 2 software & controller.

When I use either controller by itself, everything runs smoothly. When I try to use both, chaos ensues! APC becomes unresponsive, Live crashes, etc.

I could get into detail, but every time there is a different set of issues. There are many threads on the issue on Ableton´s forum. It is weird I haven´found any here, over there I found at least 20 users reporting the same issue, everyone gets different symptoms, but noone seems to get them to work together.

My questions are:
1) Is there anyone here that has both controllers and can use them without any issues?
1) From those that do have problems, has anyone found a solution or a workaround?
2) Has Ableton, AKAI or NI given any solutions or opinions on the matter?
3) Which of the three companies do you think I should pressurize most about the issue? Obviously they will start blaming each other.
4) Have I just wasted 400 euros? (Kore 2 is of no use to me if I cannot incorporate it into my gig setup.)

Any input is welcome.