If I remember correctly (as it was a long time ago) helicopters that had NACA 0012 airfoils did not have these problems. Granted there were some vibrations due to a traveling wave passing down the blade from the tip to the root but they did not cause problems as long as the blades were tracked properly. On those helicopters that did have problems with traveling wave induced vibration the problems were solved with "bob weights" or in the case of some Bell rotors they placed weight at the nodal points on the blade damping out the traveling wave.
But then again maybe I'm talking about another problem and not what is being discussed on this thread.
I personally believe that many of the problems are because of the pitching and diving tendencies of cambered blades.
