Does anybody use a Launchpad and Twitch on a WinPC?

I am trying to use Novation Twitch and Novation Launchpad (1st version) simultaneously.
When I install and connect them, the system recognizes them both and shows them in Device Manager.
But when I open a program (Ableton, Traktor or Serato), they show only the device which was connected first.

I am on Windows 7 64bit with latest updates, using the latest Novation USB Driver (also already tried the latest beta). Nothing seems to solve this.

Does anybody have the same problem or know a solution to this?

PLEASE HELP!