Apologies adding to an old thread, but I had a problem using a Nektar LX49+ as control surface, which I have managed to resolve, and thought what I found may be useful to others.
I have Sonar X1 Producer, Sonar X2 Producer, Sonar Platinum, and Cakewalk by Bandlab installed and all but one of failed to recognize anything other than basic CC and note messages - X2 was the only one that worked. I went through all the MIDI playback and record settings and only found one difference - in X2, System Exclusive was enabled but was not in the X1, Platinum or Cakewalk. Enabling this and restarting fixed the problem for me across the board.
Cheers,
Gary